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ANNUAL

OF

17

SCIENTIFIC DISCOVERY

O R,

YEAR-BOOK OF FACTS IN SCIENCE AND ART,

FOE, 1871,'

EXHIBITING THE

MOST IMPORTANT DISCOVERIES AND IMPROVEMENTS

IN

MECHANICS, USEFUL ARTS, NATURAL PHILOSOPHY, CHEMISTRY,

ASTRONOMY, GEOLOGY, BIOLOGY, BOTANY, MINERALOGY,

METEOROLOGY, GEOGRAPHY, ANTIQUITIES, ETC.,

TOGETHER WITH

NOTES ON THE PROGRESS OF SCIENCE DURING THE YEAR 1870; A LIST

OF RECENT SCIENTIFIC PUBLICATIONS; OBITUARIES OF

EMINENT SCIENTIFIC MEN, ETC.

EDITED BY

JOHN TROWBRIDGE, S.B.,

ASSISTANT PROFESSOR OF PHYSICS IN HARVARD COLLEGE;

AIDED BY

W. R. NICHOLS,

ASST. PROF. OF CHEJI1STUY IN MASS. INST. OF TECHNOLOGY;

AND

C. R. CROSS,

GRADUATE OF THE INSTITUTE.

OSTON :

G-OTJIj-D ^ IN" ID IL, I IN" C O L IN" ,

59 WASHINGTON STREET.

NEW YORK: SHELDON AND COMPANY.

LONDON: TRUBNER & co.
1871.

Entered according to Act of Congress, in the year 1871, by

GOULD AND LINCOLN,
In the office of the Librarian of Congress, at Washington.

ROCKWELL & CUURCUILL, Printers, Boston.

NOTES BY THE EDITOE,

ON THE

PROGRESS OF SCIENCE FOR THE YEAR 1870.

IN looking over the material collected during the year, which is
now embodied in the present volume, we find little that is new or
startling in the province of the mechanic arts.

Both in this country and in England attention is fixed upon
more economical and safer processes in applying inventions. The
American manufacturer would do well to read the report on
steam-boiler legislation presented at the meeting of the British
Association. Among the names of the committee who presented
it we find those of Sir William Fairbairn and Sir Joseph Whit-
worth. From the report it appears that about 50 explosions
occur in Great Britain every year, killing about 75 persons and
injuring as many others. The committee are confirmed in their
opinion that explosions are not accidental, that they are not mys-
terious ; but that they arise from the simplest causes, and may be
prevented by the exercise of common knowledge and common
care. Boilers burst simply from weakness. Competent inspec-
tion is adequate to detect the weakness of the boiler in time to
prevent explosions, whether that weakness arise from rnalcon-
struction or defective condition, while it tends to stimulate attend-
ants to carefulness, and thus to diminish the number of those
explosions arising from oversight.

The committee state that for every explosion due to the boiler-
minder in neglecting the water supply, etc., six are due to the
boiler-maker or boiler-owner from making or using bad boilers.
After discussing possible remedies the committee are convinced
that the government should enforce the periodical inspection of
all steam boilers. The numerous explosions of the year bring

this subject home to us.

Ill

IV NOTES BY THE EDITOR.

We can point with pride to some substantial engineering work
of the past year : notably, the building, launching, and placing
the great caisson at the Brooklyn terminus of the East River
bridge. An extract from the report of Col. Roebling will be
found in the present volume.

It is stated that the great central shaft of the Hoosac Tunnel
has reached the grade of the tunnel 1,030 feet below the natural
surface.

The Broadway Underground Railway is well underway ; the
construction progressing while the thoroughfare above is crowded
with its endless procession of vehicles.

The St. Louis bridge, under the able engineering skill of Captain
Eads, progresses finely.

The removal of the obstruction at Hellgate is continued day and
night. These and the work of the coast survey testify to the pres-
ence of engineering skill among us.

The European war has not called forth to a large extent the in-
ventive capabilities of our population, while it has had distinctly
this effect abroad. Activh>, however, among the American manu-
facturers of arms and ammunition has necessarily followed.

As a proof of the esteem in which American weapons are
held abroad it is stated that the Remington Co., N. Y., have ex-
ported to Denmark 25,000 breech-loaders, and as many to the
Swedish government. Colt's Co., 30,000 Berdan rifles to Russia.
Turkey has also been a large purchaser. Nearly the half of the
work of Smith & Wesson's manufactory is bought by European
parties. And the Union Metallic Cartridge Co. send their prod-
ucts to all parts of the world.

We learn, from the "London Broad Arrow," that "12 of the
Gatling guns of 45-bore have been ordered from America for the
government absolutely, and 50 additional on the understanding
that they will be taken. Meanwhile, 50 more of these guns are
being manufactured by Sir William Armstrong, at the Elswiek
ordnance works, in expectation that they also will be taken by the
government. As it is understood to be the intention of the gov-
ernment to arm each of the ships of war with a mitrailleuse, in
addition to supplying a certain number to the army, it is clear that
several hundreds of this arm will be required."

The new explosives, nitre-glycerine, dualin, lithofracteur, and
dynamite have received considerable attention during the past
year. Full accounts of dualin will be found in the present volume ;
it seems to promise well for certain kinds of work, although the

NOTES BY THE EDITOR. V

authorities at the Hoosac tunnel do not speak very favorably of it.
It consists, as do most of these new explosives, of nitre-glycerine,
with some comparatively inert base : in the case of dualin the base
is sawdust.

The manufacturers of iron are quickly adopting the latest in-
ventions, but have given us no very new modifications or im-
provements during the year.

Mechanical stoking is attracting considerable attention, and an
able paper on this subject was delivered at the meeting of the
British association, which can be found on page 23.

The European war has not added materially to the list of in-
ventions of arms of warfare. The merits of the chassepot and the
needle-gun have been actively canvassed, but on account of the
physical superiority and training of the German over the French
soldier, the trial between the weapons has not perhaps been a
conclusive one. The mitrailleuse has also come in for its share
of praise and abuse. It is thought to be a good weapon for
mowing down a close assaulting column, but not for general
field work.

It is stated that the projectiles of the chassepot and the mitrail-
leuse reached an enormous distance in the recent contests. Ac-
cording to the *' Lancet," the number of thigh wounds made by
bullets was relatively very great in the late battles ; and the
wounds made by the French sword-bayonet more difficult to heal
than those of the Prussian triangular weapon.

The loss of the " Captain " will necessarily call attention to the
safer construction of iron-clads.

At the meeting of the British Association, Captain Rowell pre-
sented his claims of the superiority of hemp cables over iron and
hemp cables, and asserted that the hemp cable would be 50 per
cent, cheaper than the present system.

The recent interruption of telegraphic communication with
Europe will result, undoubtedly, in the laying of more cables.

A cable between England and France, from Beechy Head to
Cape Antiper, near Havre, is in process of construction. It is to
be an independent line, and is much needed on account of the
pressure of business upon the other cables.

Considerable attention has been paid lately to the use of wire-
rope tramways. The late Mr. Roebling, by perfecting the manu-
facture of iron cables, undoubtedly led the way to this result. In
mining districts, on steep inclines, and even on ordinary transpor-
tation lines, the telo-dynarnic system seems destined to play an

VI NOTES BY THE EDITOR.

important part. In England, 13 lines, varying from short dis-
tances to 4 miles in length, have been constructed, and upwards of
100 miles are in course of preparation or under contract.

The Suez Canal is a successful fact.

At the meeting of the British Association, General Heine read a
paper on " Lines for Ship Canals across the Isthmus of Panama."
He concluded that only two lines were deserving of consid-
eration, because of the expense for constructing and working
them. The two lines were, first, from Aspinwall along the line
of the railway to Panama, with an extreme elevation of 269 feet,
a length of 35 miles through rocks of porphyry and basalt, and
with but middling ports of entry ; second, from the Gulf of Darien
through the rivers Atrato, Caiarica, Paya, and Tuyra, to the Gulf
of San Miguel, with an extreme elevation of 186 feet, length 52
miles, through soil composed of alluvial deposit, with some thin
ranges of grayish sandstone and schist, and with very good
ports of entry. The speaker urged upon Englishmen a greater
interest in this canal, which would so materially shorten the
marine passage to Australia, the west coast of America, and the
islands of the Pacific Ocean.

This year marks the completion of the Mount Cenis Tunnel.

The use of artificial stone is on the increase. In many regions
of our country, where stone and timber are scarce, the use of
concrete in building would seem to find favor. Among the later
inventions may be instanced that of the Rev. H. Highton, of
England, which utilizes the refuse of granite quarries.

A paper on International Communication in the present vol-
ume will prove of interest to all who are afflicted with sea-sickness.

Mr. Bessemer proposes to construct a chamber or state-room
which shall accommodate itself to the motions of the ship,
somewhat as a lamp hung upon gimbals. This chamber is to be
luxuriously fitted up, and to be carefully shut off from the air of
the boilers and engines. The expense of such an arrangement
seems to be the only feature that will militate against so desirable
an improvement.

The watering of streets with chemicals has attracted favorable
attention abroad. At the meeting of the British Association,
Mr. J. W. Cooper, who has given much attention to this subject,
stated that three streets in the city of Liverpool were watered with
salt during the month of July, 1869, with very favorable results,
so much so, that the experiments were continued this year.

Mr. Cooper proposes to add a certain portion of the deliques-

NOTES BY THE EDITOR. VII

cent chloride of aluminum to the salts used, and, by its antiseptic
qualities, afford a means of more thoroughly purifying thorough-
fares.

Photography applied to military purposes is not new, but the
English government are making greater use of it than ever
before.

Photographs are taken of soldiers exercised in the manual of
arms, both in the infantry and the artillery service; of the
lading of sumpter mules, and, in short, of everything which can
convey information to new recruits in the colonies.

The preservation of meat has long attracted much attention
in this country and in Europe. The exportation of preserved
meats from Australia is becoming a business of great impor-
tance. Since the opening of the Pacific Railroad fruit and meat
have been transported to the Atlantic sea-board in closed refrig-
erator cars. In this connection it is well to notice the increased
use of artificial ice. The French company Messageries Impe-
riales, wishing to ascertain what kind of ice would be preferable
for the vessels navigating the Suez Canal, caused experiments
to be made under identical circumstances, and apparently proved
that artificial ice would have the preference over natural ice for
transportation, and for refrigerating mixtures. More experiments,
however, are needed to establish this fact.

A paper on the continuity of the gaseous and liquid state of
matter, by Dr. Andrews, will be found on page 128 ; the transition
from the gaseous to the liquid state is shown not to be abrupt, but
that the two states are connected by a continuous change. The
writer infers, also, that liquids change to solids by a similar law.
The recent experiments made by M. Andre, on the velocity of
sound in water, give the velocity as 1206.5 metres per second.
Wertheim, it will be remembered, found it 1173 metres per second,
and MM.Colladon and Sturm, 1435 metres per second. Koenig's
investigation of the vowel sounds, supplementary to Helmholtz'
researches on the same subject, are interesting in a philological
point of view. He infers from the simplicity of the ratio of the
vibrations of the five vowel sounds found in all languages, the
reason of their universal adoption.

M. Jamin has extended the use of electric currents to the
determination of latent heats and specific heats. In this con-
nection it is well to mention Siemens 1 resistance pyrometer. This
instrument will measure intense heat ; it is based upon the princi-
ple that metals offer a resistance to the passage of an electrical

VIH NOTES BY THE EDITOR.

I

current when they are heated, this resistance increasing in a
determinate ratio. Efforts have long been made to invent an
accurate pyrometer. Experts state that this pyrometer promises
to be very useful.

The new galvanic battery, invented by Bunsen, evolves no
fumes in working, and is quite constant. Consisting merely of
one liquid, a mixture of suJphuric and chromic acids, no porous
cells are needed.

The experiments on the Atlantic Cable, conducted by Dr.
Gould, can be found on page 155.

The general reader will be interested in the fact that mes-
sages were effectually and distinctly transmitted in each direction
by the use of an electrometer formed by a small percussion cap
containing moistened sand, upon which rested a particle of zinc.

Colonel Woodward, of the Army Medical Museum, Washington,
has made a series of experiments in microscopic photography,
using the magnesium and electric lights. His results are very
successful. The lime light and the magnesium light had been
used before in this connection, in England, but not with great
success.

Measurements of Newton's rings made some years since by
Fizeau, together with the wave length of the light of the two
principal components of the D line of the solar spectrum, show
a remarkable coincidence in results obtained by different methods,
and further confirm the truth of the undulatory hypothesis. (See
page 151.)

We incorporate herewith the notes of Professor Nichols, on
the progress, during the past year, in Chemistry and Geology.

"During the year considerable progress has been made in
organic chemistry so-called. As a rule, however, much of the
work done, and most of the results obtained, appeal to the minds
of a very few even among scientific men. Still these researches
ought not to be decried by practical men, in the face of such
a brilliant result as the artificial production of alizarine. (See
page 182.) The artificial product seems to be identical in physi-
cal and chemical properties with the natural coloring matter,
and is already manufactured on a considerable scale. Worthy
of mention, also, is the synthetical construction of indigo-blue,
by Emnierling and Engler (see page 211), although the method
employed offers no prospect of its production in quantities suffi-
cient for manufacturing purposes. Moreover, our knowledge
of the constitution of chemical substances, and the laws which

NOTES BY THE EDITOR. IX

govern them is increased and rendered more certain by the
study of the more complex compounds occurring in nature, or
produced, in the laboratory. While, therefore, there is great
fascination attending the pursuit of this branch of the science,
there are still many interesting objects of research in mineral
chemistry to. be investigated, still many problems in technical
chemistry to be solved.

The definition of organic chemistry as the " chemistry of the
compounds of carbon, 1 ' felt to be so happy when first pro-
pounded, loses somewhat of its significance in view of the
researches of Friedel and others (see page 193), which show
that silicon is competent to replace carbon in the formation
of many complex bodies. That the importance of silicon in
the economy of organized existence has failed to be duly ap-
preciated cannot be denied, although we may not be prepared
to admit with Henry Wurtz, of New York City, that " all silica
in isolated forms appertains, in origin at least, to the vegetable
kingdom" The researches of Thenard (see page 196) follow
naturally those of Friedel and Landenburg.

As standing on the border line between chemistry and physics
proper, we may signalize the investigations of Thomsen, of
Copenhagen, on the heat of chemical combination. His deter-
minations differ to a considerable extent from those of Favre and
Silbermann, hitherto regarded as authority. As the result of his
experiments he finds that when a molecule of acid is neutralized
by a caustic alkali, the heat evolved increases nearly in propor-
tion to the amount of alkali added until this amount reaches 1, ,
&, |, of a molecule of alkali, according as the acid is mono-, di-,
tri- or tetra-basic. Silicic acid forms an exception to this law, as
do also, to a certain extent, arsenic, boracic, and ortho-phosphoric
acids.

In this connection allusion must be made to the researches of
Dr. Andrews, on the continuity of the liquid and gaseous states,
which tend to show that the assumption of the existence of three
distinct states or conditions of matter has no foundation in fact,
the solid, liquid, and gaseous states being actually continuous.

While we have no actual proof of the truth of the atomic theory,
and \vhile many chemists are disposed to place this hypothesis
even without the limits of probability, it is interesting to note that
Sir William Thomson, from the consideration of physical phe-
nomena, has been led so far as to calculate the size of the mole-
cules which go to make up chemical substances. He concludes

X NOTES BY THE EDITOR.

that in any ordinary liquid the mean distance between contig-
uous molecules, is less than one one-millionth of a centimeter
and greater than one two-millionth.

Dr. Angus Smith, in England, in connection with his work as
Inspector under the Alkali Act, has been carrying on chemical
examinations of the air and rain in various localities, and collect-
ing statistics looking towards the establishment of a new branch
of meteorology, chemical climatology. While the methods of
analysis are already tolerably satisfactory as far as the determina-
tion of the various gases naturally or accidentally present in the
air, and of the various saline matters contained in the rain, the
great problem bearing upon health -the determination of the
amount of organic matter in the atmosphere and its character,
whether harmless or injurious is still far from being solved.

While in technical chemistry there is little to record that is
strictly new, attention may be called to the great change wrought
in one of the most important of the applications of chemistry
to the arts, namely, the manufacture of chlorine. Weldon's pro-
cess (see page 166), announced at the meeting of the British Asso-
ciation in 1869, is supplanting the old method, to considerable ex-
tent, both in England and on the continent. That the process is,
however, still imperfect, is evident from the fact that two-thirds
of the chlorine in the chlorhydric acid employed goes to waste.
The ingenious process of producing chlorine without the use of man-
ganese, suggested by Henry Deacon (see page 169), while theoreti-
cally excellent, presents practical difficulties which have not been
surmounted so as to bring the method into actual use.

Geology. The most interesting results which have recently
been obtained have been the results of the deep-sea dredgings,
carried on along the Atlantic coast on both sides of the ocean,
with assistance from the governments of Great Britain and the
United States. The facts thus obtained in regard to the mode of
deposition of calcareous and other sedimentary rock-strata, and
in regard to the distribution of animal life, are of the highest
importance. It seems that there is no limit to the depth at
which animal life can exist; many genera and species, hereto-
fore considered extinct, have been found to have living representa-
tives ; the influence of warm and cold currents is shown to be very
great on the fauna of a given area, so that side by side deposits
are forming, one containing the remains of arctic, and another the
remains of temperate or even tropical species. A somewhat

NOTES BY THE EDITOR. XI

detailed account of the results of these investigations will be
found in subsequent pages."

Professor Huxley, in his address at Liverpool, contributed some
new terms to science.

The hypothesis that living matter always arises by the agency
of pre-existing living matter, he terms biogenesis ; and the doc-
trine that living matter may be produced by not-living matter,
abiogenesis.

It may be well also to notice two other terms greatly used in
this branch of science : homogenesis and heterogenesis, or xeno-
genesis. When the living parent gives rise to offspring which
pass through the same cycle of changes as itself, like giving rise
to like, this is termed homogenesis ; when the living parent gives
rise to offspring which pass through a totally different series of
states from those exhibited by the parent, and do not return into
the cycle of the parent, this is termed heterogenesis or xeuo-
genesis ; like not giving rise to like.

A late writer in " The Lancet " says : " The determination of
the nature and mode of existence of the contagious principles of
zymotic diseases has hitherto baffled the keenest search of scien-
tific workers ; but the employment of improved methods of observa-
tion is at length beginning to remove much of the mystery which
envelops the subject of contagion. Until we have unravelled the
nature of zymotic poisons, it is impossible to make any real prog-
ress in the discovery of efficient means of averting the spread of
epidemic and contagious diseases. From the^ results of a special
investigation, conducted for the Privy Council in England by Dr.
Sanderson, we are led to the conclusion that every kind of con-
tagion, as regards its physical form, consists of extremely minute,
separate, solid particles, to which the name microzymes is given ;
these particles being spheroidal, transparent, of gelatinous consist-
ency, of density equal to that of the animal fluid in which they are
contained, and, therefore, not deposited by subsidence, and com-
posed of albuminous matter. They are organized beings, self-
multiplying organic forms. The results of M. Chauveau's exper-
iments with small-pox, sheep-pox, and farcy poisons, all tell in
the same direction. It is apparent that the tendency of recent re-
searches is to induce a reaction in favor of the fungus origin of
zymotic disease."

"The controversy about Spontaneous Generation, or Abiogen-
esis," remarks the "Lancet," "resembles history, it continu-
ally repeats itself. Notwithstanding the discussions at the meet-

XII NOTES BY THE EDITOR.

ing of the British Association, the whole question is now rele-
gated to the region of inquiries into the degree of heat that will
be certainly destructive to the lower forms of life."

Dr. Bastian, in three articles ("Nature," vol. n., pp. 170, 193,
219), gives his reasons for believing that spontaneous generation
does occur. He criticises Professor Huxley's address before the
British Association in "Nature," vol. n., pp. 410, 431, and 492.

In the hydrated chloride of aluminium we have a new antiseptic.

At a meeting of the Boston Society of Natural History, June 1st,
1870, Mr. Edward S. Morse made a verbal communication on the
position of the Brachiopoda in the animal kingdom. After stating
observations made upon different species, especially upon the
Lingula pyramidata, and upon alcoholic specimens of Tcrebratula
and Discina, he concludes that the Brachiopods, together with the
Polyzoa, should be removed from the Mollusca, and placed with
the Articulates among the Annelids.

One cannot fail to notice that the workers in the different fields
of biology and physics are both engaged in investigating the first
conditions of matter, the one striving after a knowledge of the
germs of life ; the other investigating the size of atoms and their
existence or non-existence. Sir William Thomson, by his papers
on the size of atoms (published in "Nature," vol. I., p. 551),
has directed attention in a strong degree to Molecular Physics.

Professor Young, of Dartmouth College, has succeeded in photo-
graphing a solar protuberance. A way is thus evidently opened
for preserving records of these eruptions. An important research
upon the constitution of the sun has been published by Professor
Zollner. His results are as follows :

The forms of the protuberances are divided into two groups,
vaporous or cloudy, and eruptive. The vesicles of vapor in ter-
restrial clouds only form the means through which the differences
of masses of air become visible. The clouds of the protuberances
are made visible by the incandescence of glowing hydrogen.
Starting with the hypothesis that the eruptions are clue to the
difference of pressure of gases emanating from the interior and
the surface of the sun, and assuming that there is a separating
layer between the inner and outer strata of hydrogen, he
follows out the mechanical theory of heat and gases, consider-
ing the eruptive protuberances due to the flow of a gas from one
space into another, while the pressure in both is constant ; neither
communication nor absorption of heat being assumed. He finds
the absolute minimum temperature in the space from which

NOTES BY THE EDITOR. XQI

an eruption of 1.5 minute's height takes place, to be 40, 690 C.,
and from a protuberance of 3 minutes' height, 74, 910 C.

The maximum velocities of streams of gas moving vertically or
horizontally in the chromosphere are from 40 to 120 English milea
per second. According to the mechanical theory of heat such ve-
locities of hydrogen necessitate differences of temperature amount-
ing to 40,690 C. Having shown that the explanation of the
eruptive protuberances necessitates the existence of a separating
stratum between the space from which they emanate and the
space into which they pass, we must assume a reference to its
physical condition that it cannot be gaseous, and must, therefore,
be .either solid or liquid. The former is improbable on account
of the high temperature ; it is therefore concluded that the sepa-
rating stratum consists of an incandescent liquid.

In reference to the inner masses of hydrogen, bounded by that
stratum, two suppositions are possible : 1. The whole interior of
the sun is filled with incandescent hydrogen gas, which would
make the sun an immense bubble of hydrogen, surrounded by a
liquid glowing envelope. 2. The masses of hydrogen, bursting
out into protuberances, are local collections, in bubble-like cav-
erns, which form in the superficial layers of a liquid glowing mass,
and burst through when the presence of the confined gas in-
creases.

Under the first supposition, stable equilibrium could only exist
if the specific gravity of the outer layer is less than that of the gas
below it. Since the density of a globe of gas, whose particles are
subject to Newton's and Mariotte's laws, increases towards its
centre, the specific gravity of the outer boundary layer must neces-
sarily be less than the mean specific gravity of the sun. But if we
take the mean specific gravity of the sun as the maximum of the
liquid outer layer, we would be obliged to assume that all deeper
layers, including the gaseous one immediately below, have the same
specific gravity. Then the interior of the sun could not consist of a
gas, but of an incompressible fluid. All these properties are clearly
a necessary consequence of the supposition that the specific grav-
ity of the compressed gases forming the protuberances reaches as
its maximum the mean specific gravity of the sun.

In that case we must suppose, secondly, that the sun consists of
an incompressible liquid, near whose surface there are collections
of glowing masses of hydrogen, which break through bubble-
like caverns, as eruptive protuberances under certain differences
of pressure.

XIV NOTES BY THE EDITOR.

However small these caverns may be in special cases, the spe-
cific gravity of the enclosed gases cannot be greater than that of
the surrounding liquid, because, otherwise, the compressed gases
would sink towards the sun.

Professor Zollner finds that, calling the pressure at a certain
height above the base of the solar atmosphere, between 0.500 m.
and 0.050 m., there results a mean temperature of 27,700.

Iron must accordingly exist as a permanent gas in the solar
atmosphere ; from the value of t = 27,700 the inner temperature is
found to be 68,400, and the pressure in the interior of the space
from which the protuberances emanate is 22.1 times greater than
the pressure at the surface of the liquid separating layer ; the pres-
sure at the base of solar atmospheres being 184,000 atmospheres,
that at the interior would be 4,070,000 atmospheres, this latter
maximum pressure being reached at a depth of 139 geographical
miles below the sun's surface.

The pressure increasing rapidly towards the interior of the sun,
permanent gases, such as hydrogen, can exist only in a glowing
state in the interior of the sun.

Professor Zollner shows that the quantity of oxygen and nitro-
gen, if these gases exist in the sun's atmosphere, must be ex-
tremely small compared with that of hydrogen in that stratum
where the spectrum of hydrogen becomes continuous, and their
pressure consequently would not be indicated by absorption.

The absence of oxygen and nitrogen lines in the solar spec-
trum may also be accounted for by the slight emissive power of
permanent gases as compared with that of vaporized solids.

Professor Zollner concludes :

1. The absence of lines in the spectrum of a self-luminous
star does not prove the absence of the corresponding bodies.

2. The stratum, in which the reversion of the spectrum takes
place, is different for every body, and lies nearer to the centre
of a star the greater the density of the vapor and the less the
emissive power of the body is.

3. In different stars this stratum, other things being equal,
lies the nearer the centre the greater the intensity of gravi-
tation.

4. The distances of the strata of reversion for different bodies
from the centre of the star, and from each other, increase with
the temperature.

5. The spectra of different stars contain the more lines under

NOTES BY THE EDITOR. XV

similar circumstances, the less their temperature and the greater
their mass is.

6. The great difference of intensity in the dark lines of the
spectrum of the sun and other fixed stars depends not only on
the differences of absorption, but also on the different depths at
which the reversion of the spectra takes place.

M. Borelly, at the Marseilles Observatory, has discovered a new
planet (No. 110). Professor Peters, of Hamilton College, has
added two new asteroids (the 111 and 112) to the number
already enrolled. A new comet was discovered at the observa-
tory of Marseilles, on the 28th of August, by M. Coggin.

Professor Winlock, of the Cambridge Observatory, has had pho-
tographs of the sun taken nearly every fair day during the past
year. The primary objects in this work have been to prepare
and perfect apparatus and processes which might be used with
the best result during the coming transit of Venus, in 1874. A
reliable record of changes in the sun's surface is also obtained
by these photographs.

Mr. Proctor has published some novel views of the constitution
of the stellar system under the title of " Star Drift" and " Star
Mist."

Dr. Gould, with assistants, is now stationed at Cordova, in the
Argentine Confederation, having the observatory there under
his charge. He proposes to extend the catalogue of the south-
ern heavens beyond the limit of 30, to which the zones of Arge-
lander extended. Dr. Gould says, "My hope and aim is to
begin a few degrees north of Argelander's southern limit,
say at 26 or 27, and to carry southward a system of zone
observations to some declination beyond Gilliss 1 northern limit,
thus rendering comparisons easy with both these other labors,
and permitting the easy determination of the corrections need-
ful for reducing positions of any one of these three series to cor-
responding ones for the other."

Great preparations were made to observe the total eclipse of
the sun in December, Professor Pierce, of Harvard College, in
his official capacity as superintendent of the coast survey, having
general charge of the American expedition.

After crossing the Atlantic Ocean, the shadow of the moon
passed across the south of Portugal and the Straits of Gibraltar to
Algeria, reaching its most southerly limits in about longitude 4
east of Greenwich, where the southern boundary of the shadow-

XVI NOTES BY THE EDITOR.

path was in about 34f north latitude. Thence the shadow passed
to Sicily, the northern limit passing slightly to the north of Mount
Etna, and so, touching the extreme southern point of the Italian
peninsula, by the south of Turkey, past Thessaly. The most im-
portant parts of the shadow's path were those across the south of
Portugal and Spain, in Algeria, and across Sicily. The chief
towns which lie close to the central line are Odemira, Silves,
Almodorar, Tavira, Ayamonte, Huelva, Palos, Jeres, Cadiz, San
Fernando, Arcos, Estepona, and Marbella in the Spanish penin-
sula ; Oran and Ratna in Africa ; and Syracuse in Sicily.

The following letter from Professor Young, on the observations
at Jeres, Spain, appeared in the New York Tribune :

" By the courtesy of Professor Wiulock I am permitted to com-
municate the general results of our observations on the eclipse.
I think I may say that on the whole our expedition has been
highly successful, though more might have been accomplished
had the weather been better. We seem, however, to have been
more favored in this respect than any of the English parties ob-
serving in Spain. From those in Algeria and Sicily I have not
yet heard.

" The day and night previous to the eclipse were very fine, but
early in the morning it clouded over, and when we arose the pros-
pect was very gloomy. It even rained from time to time. We
made all our observations, however, and before first contact
(10.25 A.M., local time) there were many patches of partly clear
sky, but there was always, even when clearest, enough haze of
frost crystals to cause the sun to be surrounded by a conspicuous
halo of 22 radius. At the time of first contact, it was clear
enough to allow good observations to be made in the usual
method. I attempted to use the spectroscope upon it in the
same manner as last vear, but failed on account of the thin cloud

/

which most of the time entirely obliterated the chromosphere lines.
" Between time of the first contact and totality, there were
several intervals of moderate clearness, in which photographs of
the partial phases were taken. Just before totality the clouds be-
came much thicker, and we nearly gave up hope ; but at the
needed time, almost by the direct interposition of Providence, as
it would seem, a small rift in the now heavy clouds passed over
the sun, and permitted us to observe the sublime phenomenon, if
not in all the beauty and sublimity of last year, yet satisfactorily
and most gratefully. Within five minutes after the end of totality
the sky was wholly clouded, and we did not see the sun again

NOTES BY THE EDITOR. XVII

until near evening, after a heavy storm of wind and rain. During
the totality, one good photograph of the corona was obtained with
the 6-inch glass, with an exposure of 1 minutes. It is, of course,
by no means so good as it would have been had the sky been
truly clear ; but it shows a great deal of detail, curved filaments
and radial shadings far better than ever before obtained. The
picture produced with the 8-inch glass was injured by not being
removed until the sun came out. No attempts were made to pho-
tograph the prominences, which can be seen and studied at any
time. All efforts were concentrated on the corona.

"In respect to the polarization observations, there is reason to
suppose that there must have been some peculiar defect in the
particular instrument Professor Pickering used last year, as his
assistant, Mr. Ross, using it on this occasion, obtained the same
unsatisfactory result. But apparently similar instruments, used
this year, together with others quite different in construction, in-
dicated radial polarization of the corona. The appearances in the
instruments were much complicated by the cloud and haze, but
I believe Professor Pickering and Professor Lang-ley both a-oree

O / o

that the corona certainly has a considerable proportion of its light
radially polarized. Our spectroscopic results completely confirm
those of last year, and except that the two faint lines which I saw
between D and E last year, and suspected to be corona lines as
well as 1474, were not seen at all this time ; 1474 was traced by
Professor Winlock to a distance of nearly 20 minutes from the
sun's limb. I traced it 16 minutes on the west, 12 on the north,
14 on the east, and about 10 on the. south. The principal chro-
mosphere lines were also visible in the corona to a distance of 3 or
4 minutes. Professor Winlock and myself both agree in attribu-
ting this to the reflection of the haze around the sun. I am more
confident as to this, because last year, in a clear atmosphere, the
C line was certainly sharply terminated at the upper limit of the
chromosphere or prominences under observation. Mr. Abbay, in
his spectroscope, saw only the 1474 line and the F line, the
former was considerably the brighter of the two. He saw no con-
tinuous spectrum.

" But the most interesting spectroscopic observation of the
eclipse appears to me to be the ascertaining at the base of the
chromosphere, and, of course, in immediate contact with the
photosphere, of a thin layer in whose spectrum the dark lines of
the ordinary solar spectrum are all reversed. Just previous to
totality I had carefully adjusted the slit tangential to the sun's

XVIII NOTES BY THE EDITOR.

limb at the point where the second contact would take place, and
was watching the gradual brightening of 1474, and the magne-
sium lines. As the crescent grew narrower, I noticed a fading
out, so to speak, of all the dark lines in the field of view, but was
not at all prepared for the beautiful phenomenon which presented
itself when the moon finally covered the whole photosphere.
Then the whole field was at once filled with brilliant lines, which
suddenly flashed into brightness, and then gradually faded away
until, in less than 2 seconds, nothing remained but the lines I had
been watching. The slit was very close, and the definition per-
fect. Of course I cannot positively assert that all the bright lines
held exactly the same position that had been occupied by dark
ones previously, but I feel very sure of it, as I particularly noticed
several groups, and the whole arrangement and relative intensity
of the lens struck me as perfectly familiar. Mr. Pye saw the
same thing, for an instant only. Professor Winlock did not, as
his telescope at the time, in accordance with his directions, was
pointed to a spot at some distance from the sun's limb ; neither
did Mr. Abbay see it.

*' This observation is a confirmation of Secchi's continuous
spectrum at the edge of the sun, and, I think, tends to make
tenable the original theory of Kirchoff as to the constitution of
the sun, and the origin of the dark lines in the ordinary solar
spectrum."

General E. Abbott, in a letter to Professor J. E. Hilgard, states,
" We have settled that the corona, in part, at least, is solar. The
light is strongly polarized in radial planes."

Professor Peirce says, in a letter, " that the true corona is
proved to be a solar atmosphere, extending about 80 miles above
the visible surface of the sun, there being three different sources
of proof of this."

Lockyer, in his report, in *' Nature," of January 19, asserts
that the corona is a compound phenomena, arising some 5' or
6' high around the moon, with a light beyond, which different
observers have noted differently, now stellate with many rays ;
now stellate with few; now absolutely at rest; now revolving
rapidly.

From the spectroscopic observations, Lockyer thinks that the
chromosphere may be built up of the following layers, which are
in the order of vapor density in the case of known elements :

NOTES BY THE EDITOR. XIX

X ' (new element) green coronal line

TT , c Sub-incandescent. F

Hydrogen )

Incandescent, C, F, near G, h

X (new element), near D

Magnesium, b, und lines in bluo and violet

Sodium, D

Barium, several lines

Iron, etc., several lines, including E

He further says : " The foregoing table excludes naturally the
substance or substances which give bright lines in the solar spec-
trum, which are visible at times in the spectrum of the chromo-
sphere. I have ventured to suggest that the substance which
gives the line in the green is a new element, because invariably
I have found that in solar storms the atmospheric layers are
thrown up in the order of vapor density, and because all the
heavier vapors are at or below the level of the photosphere
itself "

" Parties in Sicily obtained evidence that the corona was radially
polarized. Hence the corona not only radiates, but reflects solar
heat to us."

Lockyer offers as suggestions :

" 1. The solar chromosphere extends some 5' or 6' from the sun
(Watson and others), its last layers consisting of cool hydrogen
(Mr. Abbay), and possibly a new element with a green line in its
spectrum (Young, Barton, and others) ; which line, if it be identi-
cal with the auroral line, as stated by Gould, may possibly be
present in the higher regions of our own atmosphere.

"2. Outside this stratum the ra} T s, etc., are for the most part
due partly to our own atmosphere, partly to our eyes, for their
shape varies ; they are seen by some at rest, by others in motion,
and their spectrum is the same as that of the dark-moon (Maclear).

"3. The white light of the chromosphere above the prominences,
as seen in an eclipse, is clue to its strong reflection of solar light,
as shown by the polariscopic observations (Ranyard, Peirce, Jun.,
Ladd) .

"4. The rosy tinge of the corona proper, that is, of the region
more than 5' or 6' from the sun, is due to our atmosphere contain-
ing light which comes from both the higher and lower strata of
the chromosphere (Peirce, Sen., Maclear, Abbay)."

Professor Winlock found a faint, continuous spectrum without
dark lines.

1474, Kirchoff, was found all round the sun to a distance of 20'

XX NOTES BY THE EDITOR.

from the disc, and appeared to be the most conspicuous corona
line.

Professor Winlock also states the probable existence of an en-
velope surrounding the photosphere, and beneath the chromo-
sphere, of a thickness from 2 to 3 seconds of arc, which gives a
discontinuous spectrum of all the ordinary lines, bright on dark
fields.

Professor Pickering, observing with an Arago polariscope, one
of the four employed by Prazmowski and Savart, obtained with all
three results pointing to a radial polarization of the corona. The
light covering the moon's disc he observed to be polarized
throughout in the same plane, and the observations showed that
the Arago and other polariscopes dependent on color were suffi-
ciently delicate to determine this plane with accuracy.

A writer in "Cosmos," of July 30th, sums up the progress of
geography for 1869-1870. We give the following abstract :

Each year the space of unknown lands on the surface of the
globe grows smaller; but the investigations relative to different
branches of geography embrace an immense field.

The completion of the Suez Canal and the Pacific Railroad open
extended ways for scientific exploration.

Africa and the regions of the North attract, at present, the prin-
cipal attention of geographers. In Africa, the Abyssinian war
has brought out many treatises upon this particular region. An
Italian scientific expedition at the present moment is engaged
there.

A German traveller, to whom we owe interesting studies upon
the shores of the Red Sea, has also explored the bordering
regions of Nubia in the country of the Djours, where he is occu-
pied principally with ethnographic researches.

Dr. Schweinfurth, after a long residence among the Africans,
confirms the opinions of M. de Quatrefages, that the coloration
of the skin cannot serve for the distinction of different races.

In the region of the great lakes of Equatorial Africa, Living-
stone pursues his discoveries with a courage not abated by
obstacles.

May 30, 1869, at Ujiji, he was preparing to trace a new lake
at the west of Tanganyika, from which flows a great river, it
may be one of the sources of the Nile, which thus finds itself
again reported more to the south. In the south-east there are
the travels of Erskine upon the borders of Limpopo, those of
Fritsch, of Mauch, which have given hopes of rich auriferous de-

NOTES BY THE EDITOR. XXI

posits in the interior of Zambkze, but the difficult courses of which
have profited more to geography than to the seekers of gold.
We have had recently an account of the expedition of Lieuten-
ant Aytnes, of the French marine, in the basin of VOgovt from
the side of Gabon, which has contributed some precious materials
for natural history.

Gerard Rohlfs has visited the oasis of Cyrenaique.

Wallace has published an article upon the Malay Archipelago ;
Dr. Sempor upon New Guinea; Professor Bastion upon Sin-
gapore, Batavia, and Manilla ; and M. Gamier, a memoir upon
the migrations of the Polynesians, published in the Bulletin of
the Geographical Society.

In regard to Asia, attention is called to the works of M. Her-
man de Schlagintweit upon India ; of M. Charles Lemire, upon
Cochin China, and of M. Francis Gamier, upon the French ex-
pedition to Mekong.

In China, Cooper has pushed his explorations into the heart
of the empire in the basin of the Yang-tse-kiang ; while another
traveller, M. de Richoffen, occupied himself with geological re-
searches upon the frontiers of the north beyond the great wall ;
and a French missionary, P. Armaud David, has employed the
leisure hours of his office in the study of the natural history of
Thibet and Mongolia.

Upon the confines of Siberia the Russians have finally fixed
the limits between their Asiatic possessions and China; at the
same time they continue their explorations into Central Asia,
as much from the political point of view as in the interests of
science. Those desiring ampler details of the progress in
geography will find them in the report made by M. Charles
Mannoir to the Geographical Society, or in the selections of the
" I/Annee Geographique " of M. Vivien de Saint Martin.

In Central America the piercing of the Isthmus occupies public
attention. Malte-Brun enumerates no less than 28 projects for
a canal across the isthmus. To these different projects it is
necessary to add those of M. du Puydt, and of Commander
Selfridge, who commands the latest expedition to explore the
routes. In expectation of the realization of these projects, the
government of Honduras has ordered the construction of a rail-
road setting out from the port of Puerto-Cabello, upon the
Atlantic, and ending in the Bay of Fonseca, upon the Pacific.
These important works are indicated because they will have an
important bearing upon many branches of geography.

XXII NOTES BY THE EDITOR.

Attention is also called to the publication of Poncel, upon the
Argentine Republic ; the researches of Agassiz upon the Ama-
zon ; the geological studies of M. Guillemin Taragre, in Mexi-
co, and the expedition of Whymper, in Alaska.

Moyne has made a visit to the Strait of Magellan, and to the
country of the Patagonians.

In Australia one signals the expedition of John Forrest into the
interior of the eastern part of the continent as far as 123 of east
longitude from Greenwich. The report published by the governor
of the State of Victoria, under the title of "Auriferous Deposits
and Mining Districts of the Province of Victoria," by Mr.
Brought Smith, is also cited upon this region.

Proceeding eastward from the Sea of Aral, the Russians have
rendered the river Syr Daria navigable by steam vessels of a lim-
ited size, and, fixing military posts on its banks, have ascended
towards its sources, and taken possession of the populous and
flourishing city of Tashkent, a great mart of caravan commerce.
Russia has also triumphed over the Khan of Bokhara. The appre-
hension that these advances of Russia would prove prejudicial
to British India is losing ground in England.

The industrial classes of the United States have been the sub-
ject of a long and interesting report by Mr. Francis Clare Ford,
Secretary of the English legation, at Washington. This report
was made in pursuance of a circular addressed by Lord Clarendon,
in April, 1869, to the diplomatic and consular agents of Great
Britain, instructing them, to report upon the condition of the in-
dustrial classes in the countries to which they were accredited. Mr.
Ford says that the American system of common-school education
has elevated the condition of the native-born working man, and
has disposed him to prefer occupations in which the exercise of
the brain is in greater demand than that of the elbow, and
asserts that the steady influx of immigrants for the last twenty
years has created a disinclination on the part of American work-
men to engage in the rough toil of purely muscular labor which
the newly arrived foreigner is ready to exert for his support.

It will be recollected that in the "Annual of Scientific Discovery "
of 1870, we noticed the enactment passed by the Massachusetts
Legislature to provide instruction to the working-classes in me-
chanical drawing. Several of these schools are now in opera-
tion, and constitute, we think, the germ of a brighter future.

THE

ANNUAL OF SCIENTIFIC DISCOVERY.

MECHANICS AND USEFUL ARTS.

MECHANICAL STOKING.

THE folio-wing interesting paper was read, at the meeting of
the British Association, in Section G (Mechanical Science), by
Mr. James Smith, of Messrs. T. & T. Vicars, engineers, Seel
Street, Liverpool :

"Our reasons and apology for bringing under your notice the
subject of mechanical stoking are, first, the importance to the
mechanical engineer of everything that relates to furnace man-
agement, and especially the importance of any improvement that
will enable him to have the slavish labor of stoking performed by
a machine that will more efficiently discharge the required duty
than human labor can ; and this, I conceive, is always the case
when a machine is successfully applied to any purpose. Sec-
ondly, the visit of your society to our town enables us to submit
to the judgment of a competent tribunal the merits or defects of
a system of mechanical stoking that we have applied and are ap-
plying largely in different parts of the country. All who have
had any experience in furnace management are aware that the
duty obtained from a boiler or other furnace depends to a very
great extent on judicious stoking, and one of the troubles of the
practical engineer is to obtain the services of stokers upon whom
he can rely. Several writers on the subject have directed atten-
tion to the desirability of substituting mechanical for hand stoking

> o

as the only means of securing economy, efficiency, and smoke-
lessness. Bourne, in his work on recent improvements in the
steam engine, published last year, says : * In steam vessels it is
most desirable that some proper species of firing apparatus should
be employed, as the labor and difficulty of firing large furnaces
at sea, especially in hot climates, is very great. I believe that a
good smokeless furnace and a good self-feeding furnace will
come together,' Considering the acknowledged importance of

23

24 ANNUAL OF SCIENTIFIC DISCOVERT.

the subject, it does seem remarkable that so little has been done
in this direction. Of the different lire-feeding machines, as they
have .been called, that have been employed at different times, I
think I am correct in stating that, excepting the one I wish to
bring under your notice, Juckes' Endless Chain Grate is the only
one that has received any considerable amount of approval. Of
the performance of this furnace very conflicting accounts are
given ; but I believe that under favorable conditions as to fuel,
management, and work to be done, when applied to externally
fired boilers the performance of this furnace has been found sat-
isfactory. Although the Juckes' grate does, under favorable cir-
cumstances, prove the superiority of mechanical over hand stok-
ing, yet it does not, I think, sufficiently meet the engineering
requirements of the present time ; it has one serious defect : it is
only applicable to externally fired boilers, and is very cumbrous.
Before describing particularly our furnace, I will speak of what
I conceive ought to be aimed at in constructing a mechanical
stoker.

"The late Mr. Charles Wye Williams, who has done so much
to diffuse and popularize correct views on the subject of furnace
management, writes, in his work on the combustion of coal and
the prevention of smoke : ' The facility with which the stoker
is enabled to counteract the best arrangements naturally suggests
the advantage of mechanical feeders. Here is a direction in
which mechanical skill may be successfully emploj^ed ; the basis
of success, however, should be a sustaining at all times the uni-
form and sufficient depth of fuel on the bars.' This is correct so
far as it goes, but a mechanical stoker, to be successful, must do
more than this : it must preserve the air spaces of the fire grate
uniformly open, be self-cleansing by discharging the ashes, slag,
or clinker as formed ; and, in addition, I think it is important that
the fuel should be introduced at the front of the furnace, and
should have a progressive motion towards the bridge. The ad-
vantage of introducing the fuel at this part, as a means of insur-
ing economy and preventing smoke where bituminous fuel is
used, has been proved conclusively by numerous experiments. I
suppose the cause of this is the long run of the volatile hydro-
carbons over the incandescent fuel that fills the bridge part of the
furnace. It is also important that the machine stoker should be
easily regulated and controlled for the purpose of adjusting the
supply of fuel to the work to be done, and that it should be very
little liable to derangement, or wear and tear. I think our appa-
ratus fulfils all these conditions. Like all fire-feeding machines,
it is provided with a hopper or fuel receptacle ; the fuel is forced
into the furnace by two plungers or pushers (having an alternate
motion) at a level of about 6 inches above the bars. In very
wide furnaces we use 3 plungers, and the shaft that works the
plungers is moved by a ratchet. A very simple arrangement
enables the attendant to vary the rate of feed by causing the div-
ing eccentric at each stroke to take a lesser or greater number of
teeth. Progressive motion is given to the fire by causing the bars
to move forward en masse, and bringing them back in detail. The

MECHANICS AND USEFUL ARTS. 25

cleansing of the bars is also effected by this motion : the bars
have a stroke of about 3 inches, and we find in the average of
cases that a complete stroke about every 2 minutes is sufficient
to give the progressive motion necessary to maintain a proper
thickness of fire. As the bars themselves form an important part
of the machine, we have found it necessary to make special pro-
vision for their preservation. Each movable bar is provided with
a trough containing water, and there is a centre rib cast on each
bar which is immersed in the water. The other part of the bar
forms a perfect cover for the trough to exclude ashes, etc. ; these
troughs are supplied with water from a small cistern, and the
level is maintained by a very sensitive float and valve. In conse-
quence of the slow motion of the machine, veiy little wear and
tear occurs in the working parts. There is no part of the appa-
ratus exposed to any injurious action of fire except the upper sur-
face of the bars, and these are effectually protected by the trough
arrangement. Our experience shows that with moderate care
the amount of wear and tear is not greater than what occurs in
most ordinary furnaces.

" With regard to the economical results obtained, you will find
some particulars given in our circular. As compared with the
best hand-firing, where ordinary fuel is used, the results do not
exceed 10 to 12 per cent. We find that the system adopted by
the careful stoker and the machine system are very similar. In
both cases frequent charges at short intervals are adopted instead
of heavy charges at longer intervals ; but, in the case of hand-
firing, the incessant opening of the doors, and the interruptions
caused by cleaning the bars, are drawbacks that are avoided in
the machine. Of course, when the machine is compared with
ordinary random hand-firing, its economical superiority is very
decided ; but the chief source of economy arises from our being
able to use the smallest and cheapest fuel, fuel much of which
cannot be used at all in ordinary hand-fire furnaces. The saving
from this cause varies in different districts, and will range.from
20 to 100 per cent. In most cases, perhaps, the appreciation that
leads to the adoption of any machine or system is the most satis-
factory evidence of its value ; yet this is not a rule without
numerous exceptions, and on no subject is there more reasonable
ground for a justifiable scepticism as to the merits of any remedy
that may be propounded than that of smoke prevention. For
many years the public have had plans constantly brought under
their notice that were to end the nuisance arising from smoke,
but it still continues a very substantial nuisance, and appears to
have a very wonderful vitality. As evidence of approval of the
furnace, I may state that since we commenced manufacturing this
form of furnace, about 18 months ago, we have fixed and put
to work more than 120, with the most satisfactory results, and
approval of the furnace is extending. We are at present sending
out more than 20 per month ; in the town of Bradford alone,
which appears to be taking the lead in the enforcement of sanitary
improvements we have orders for between 50 and 60 furnaces in
a single street or road, Thornton Road.

2G ANNUAL OF SCIENTIFIC DISCOVERY.

"To prevent misapprehension it is as well to state that we have
been, for a period of 5 or 6 years, engaged perseveringly in
efforts to perfect mechanical stoking, but our first attempts were
only partially successful. Our first grate was a modified Juckes ;
but we soon found the wear and tear so considerable that we had
to turn our attention to discover some means of remedying these
very serious defects, and for more than 3 years we were en-
gaged in extensive experiments involving much thought and
money expenditure. The result is the machine I have the honor
to bring under your notice."

Mr. Lavington E. Fletcher, C.E., said he had witnessed some
very carefully conducted trials with this apparatus used against
careful hand-firing, and the results were very satisfactory. The
chairman said there was no doubt that mechanical stoking must
be superior to hand stoking. Such an apparatus as had been
described by Mr. Smith was wanted, and it was only a question
of cost. Mr. Smith then thanked the chairman and gentlemen
for their attention, and said he would be glad to show any gentle-
man the furnace at work who would favor Messrs. Vicars with a
visit to their works, Seel Street, Liverpool.

EFFICIENCY OF FURNACES AND MECHANICAL FIRING.

Having for some time past given a large share of my attention
to the subject of the efficiency of furnaces, I have to bring before
you a few results of my experience in this most interesting and
important inquiry.

Since the time in which W} T e Williams lived and labored, Pro-
fessor Tyndall and Dr. Frankland have shown that the energy of
combustion is within wide limits independent of the density of
the air, the natural inference at first sight being that in furnaces
the temperature of the air does not affect the efficiency. One of
V\ r je Williams' well-known experiments was to introduce a bent
plate' perforated with 56 half-inch holes into the centre of a fur-
nace where one or two bars had been removed for its reception.
"Adequate mixture," says Mr. Williams, " was thus instantly
obtained, as in the argand gas-burner ; the appearance, as viewed
through the sight-holes at the end of the boiler, being even bril-
liant, and as if streams of flame instead of streams of air had issued
from the numerous orifices. It is needless to add that nowhere
could a cooling effect be produced, notwithstanding the great
volume of air introduced."

Now I cannot at present do more than state the simple fact that
I have tried similar arrangements in many different instances
and under several different conditions, and that I have rarely
failed to produce a cooling effect. The arrangement by which
the results have been arrived at may be thus described : A few
of the ordinary fire-bars are removed from the centre of the flue.
A pair of longitudinal bearers about 6 inches apart are then intro-
duced, their upper surfaces being level with the common fire-
bars. On these bearers are placed small arched transverse bars,
each about 1 inch thick, in contact with one another. Semi-circu-

MECHANICS AND USEFUL ARTS. 27

lar holes are cast in the transverse surface of these bars, so that
when placed together on the bearers they present the appearance
of a tunnel about 9 inches high pierced with numerous small
holes, an arrangement not differing widely from that of Wye
Williams, except that the tunnel, being of loose cast-iron pieces,
is no more liable to deterioration by heat than common fire-bars. If
the mere fact of admitting air to the hydrocarbons at the moment
of their generation, and in minutely divided lines, is sufficient to
insure their combustion, surely nothing could do so more effect-
ually than this arrangement. But the result.

A~large quantity of fuel being placed upon the incandescent car-
bon in the furnace, we have, after the expiration of a few seconds,
a splendid display of white flame, not entirely smokeless, but com-
paratively smokeless, unless the quantity of air admitted is very
large ; white flame and intense heat, evidence of the precipitation
of the carbon particles and of their combustion after precipitation ;
smoke-burning, not smoke-prevention; greatly increased tem-
perature of the furnace-door, evidence of increased radiation of
heat. But, as I said before, in almost all cases a loss of efficiency in
the furnace, a reduction in the absolute temperature of the flame.
Was Mr. Williams deceived by that radiant heat ? I cannot avoid
the conclusion that he was in some cases at least. But the fur-
naces adopted with economical results contained elements not yet
described. The ash-pit was divided into 3 chambers by 2 vertical
sheet-iron partitions, made fast to the longitudinal bearers in
such a manner that all air entering it at the central chamber must
pass through the arched bars, while that entering by the two side
chambers reaches the fuel in the ordinary manner. Now, observe
the difference : Here we have a long central fire-chamber open to
the air only at one end. The air before entering the fire-cham-
ber passes over the surface of highly heated sheets of iron, trav-
erses in turn the cross-pieces of the little arched liars and the
heated surface of the ribs. Even with this simple change the
results are, I believe, in all cases, altered from failure to success.
A heating effect has been obtained where a cooling effect only
could be produced before.

To sum up my own observations on this subject, I find : (1.)
That the admission of cold air in quantities sufficient for the com-
plete combustion of the gases in ordinary furnaces is attended
with a loss of efficiency in all cases, even if that admission takes
place in finely divided streams immediately over every portion of
the fuel from which the gases are rising. Radiant heat, and con-
sequent temperature of the furnace door, are enormously in-
creased; smoke, however, is considerably reduced. (2.) That
by the comparatively slow motion of air over heated surfaces, and
its consequent rarefaction and increase of velocity when issuing
from the orifices of the arched bars, a much more perfect chemi-
cal union is insured. The flame is not so luminous, but a higher
rate of efficiency is obtained. Radiant heat is decreased, the fur-
nace door is rendered less hot, and smoke is more perfectly
prevented. The old Cornish system of dead-plate firing, when
conducted very carefully, and in such a manner that the incan-

28 ANNUAL OF SCIENTIFIC DISCOVER?.

descent fuel at the back of the furnace is never allowed to burn
into holes, has, as we all know, certain advantages. Bat when
the back of the furnace is left to itself, I believe it to be a most
difficult matter to avoid the admission of cold air en masse, a con-
dition which cannot but be attended with loss of efficiency; and
in my attempts to discover the best method of mechanical firing,
I could not find that those systems in which the coal had a pro-
gressive motion from the front to the back were free from these
defects. Such methods appear to me to owe their advantages,
for no doubt they have advantages, to other causes than that of
the perfect combustion of the hydrocarbons ; and is not the com-
parative freedom from smoke in this system of firing the result,
in a great measure, of that union of carbon from the front with
carbonic acid from the back, producing carbonic oxide, and inev-
itable loss of heat, the pernicious prjnciple resorted to by a whole
army of smoke-burning patentees ? The apparatus which appears
to me most correct in principle does not profess to compete with the
more perfect mechanical stokers, inasmuch as the clinkers are
removed by the firemen in the ordinary manner. In short, since
my attention was drawn to the subject, I have come to the con-
clusion that the principle of what was probably the first attempt
ever made in mechanical firing I speak of Stanley's patent is
capable of the highest possible efficiency. Twenty years ago
nearly every furnace in Lancashire was fed by the apparatus pop-
ularly known as the "hopper." In a box on the front of each
furnace 2 fans revolved horizontally. Fuel was drawn from a
hopper by rollers which crushed and let it fall on to the 2 fans,
which in their turn propelled it into the furnace. It was possible
to adjust the speed in such a manner that the fuel was spread
uniformly over the whole surface of the bars. I would merely
add that when the 2-flued Lancashire boiler replaced the
wagon and egg-ended boilers then in use, the hoppers Avere
taken down, possibly in some places applied to the new flue
boilers, found not to throw the fuel evenly over the bars, and
discarded. In Leeds, however, they are still in use to a consid-
erable extent, probably because some makers there took the
trouble to adjust them to their altered circumstances. For a
single 2-flued boiler the hopper, as now in use at Leeds, re-
quires about 20 toothed wheels, and at least 2 worms to drive the
crushers and other portions ; and notwithstanding the fact that
the teeth of those wheels are constantly breaking, and that the
whole apparatus trembles under the sudden check caused by a
large lump of coal falling between the small crushing rollers,
manufacturers who have tried it for so many years give universal
testimony as to its economy. I understand that one engineer in
Leeds still makes a considerable number of them. This appara-
tus does not, of course, prevent smoke, but it distributes the
smoke from a given quantity of fuel over a longer period than in
hand-firing, and reduces its blackness in the same proportion.

Now, does it not appear that if we can retain the manner of
throwing on the fuel, very considerably simplify the means, and
use it in conjunction wiLh the lire-bar arrangement already de-

MECHANICS AND USEFUL ARTS. 29

scribed, we shall have a very efficient furnace and a perfect pre-
venter of smoke ? The 20 toothed wheels and 2 worms have
been reduced to 1 worm and wheel ; the 2 hoppers (one over
each flue) to 1 hopper in the middle of the boiler face. The
crushing rollers have been done away with altogether, and an
arrangement substituted which crushes and metres the fuel as
effectually but much less suddenly. Through the fuel in the
middle of the hopper passes a cast-iron screw, with a tapering
helix of small diameter at the centre, but increasing gradually up
to the internal diameter of its containing c} 7 linder outside the hop-
per. The 2 halves of this screw are right and left handed,
respectively. It has a slow revolving motion, and its action on
the coal contained in the hopper is evidently of a nibbling kind,
while it metes out to the fans of each flue the desired quantity of
fuel. There are other details which have not been overlooked,
such as the well-known heaping up of the coal on the dead-plate,
the cause of which has been entirely removed. And last, but not
least, the whole machine is fixed to a frame made fast to the
boiler, by 3 bolts through the shell, no holes whatever being
cut in the boiler face. The fires made by this apparatus are per-
fectly level, and are absolutely free from even light smoke.

I hold in my hand a report prepared about 4 months ago, on
the efficiency of the apparatus in question. It is founded on very
carefully made evaporative experiments, the conclusion being
that the feeder, when used for the first time in competition with
the best hand-firing that could be obtained, gave an increased
efficiency of 9.696 per cent, over and above the efficiency already
attained with the argand furnace alone. The cost of the com-
bined apparatus is, of course, much lower than that of any of the
more elaborate mechanical stokers, little more than one-half;
but I believe the efficiency is higher. 0. E. Deacon, British As-
sociation.

MANUFACTURE OF RUSSIA SHEET IRON.

Herbert Barry, Esq., late director of estates and iron works
of Vuicksa, thus describes the manufacture of sheet iron in
Russia :

" The refined iron is hammered under the tilt-hammer into
narrow slabs, calculated to produce a sheet of finished iron 2
archimes by 1 (56 inches by 28 inches), weighing when fin-
ished from 6 to 12 pounds. These slabs are called balvanky.
They are put in the reheating furnace, heated to a red heat,
and rolled down in 3 operations to something like a sheet,
the rolls being screwed tighter as the surface gets thinner.
This must be subsequently hammered to reduce its thickness and
to receive the glance. A number of these sheets having been
again heated to a red heat, have charcoal, pounded to as impal-
pable a powder as possible, shaken between them through the
bottom of a linen bag. The pile then receiving covering and a
bottom in shape of a sheet of thicker iron, is placed under a
heavy hammer ; the bundle, grasped with tongs by two men, is

30 ANNUAL OF SCIENTIFIC DISCOVERY.

pocked backwards and forwards by the gang, so that every part
may be well hammered. So soon as the redness goes off they
are finished, so far as this part of the operation goes. So far
they have received some of the glance, or necessary polish ; they
are again heated, and treated differently in this respect, that in-
stead of having powdered charcoal strewed between them, each
two red-hot sheets have a cold finished sheet put between them ;
they are again hammered, and, after this process, are finished as
far as thickness and glance go.

"Thrown down .separately to cool, they are taken to the
shears, placed on a frame of the regulation size, and trimmed.
Each sheet is then weighed, and, after being thus assorted in
weights, they are finally sorted into first, second, and thirds, ac-
cording to their glance and freedom from flaws and spots. A
first-class sheet must be like a mirror, without a spot in it.

"100 poods of balvanky make 70 pounds of finished sheets;
but this allowance for waste is far too large, and might easily be
reduced. 4 heats are required to finish.

" The general weight per sheet is from 6 to 12 pounds, the
larger demand being from 10 to 11 pounds, but they are made
weighing as much as 30 pounds, and may then almost be called
thin boiler plates, being used for stoves, etc. Besides the fin-
ished sheets, a quantity of what are called red sheets are
made, which are not polished, and do not undergo the last
operation.

" Taking the Michsslofskoi Works, which are the largest sheet-
iron ones in the empire, I found that the power running the sheet
rolls was equivalent to 40 horses, the rolls making 70 to 80 revo-
lutions a minute. The hammers used are powerful, 'having the
surface of the stroke very large, just the contrary shape ^here
to the ordinary tilt-hammer. A gang turns out in a shift from
450 to 500 sheets.

"In the Central Works, where they make sheet iron from pud-
dled iron, they roll it into the necessary size, and then roll this
balvanlty into half-ready sheets with the same sort of rolls as are
used in the North, but which, however, run much slower; the
finish being given also by hammers in the same manner, but
leaving out the final part of the operation of placing cold fin-
ished sheets between the hot unfinished ones. The hammers are
not so heavy, and the heating furnaces are not so well constructed
and do not regulate the flame as well. The trimming, sorting,
etc., are carried out in just the same way.

"The waste is really greater in the Central Works than it
should be in the North, as the hammered iron does not leave such
a raw edge as the puddled.

"A fact that proves the superior manufacture of the North
over the north parts of the empire is, that whereas in the former
sheet iron is the best paying, in the latter it is the worst busi-
ness. . . .

" For the uses to which sheet iron is put ductibility is of the
first consequence, and no sheet iron is of passable quality that
that will not bend 4 times without breaking ; some made in the

MECHANICS AND USEFUL ARTS. 31

Oural I have bent as many as 9 times without showing the break.
Coupled with this quality the glance must be taken into consider-
ation, as good polished iron will not take so much paint as the
inferior polished." Bulletin of the American Iron and Steel
Association.

COAL AND SMOKE CONSUMPTION.

On the Pennsylvania Railroad, experiments are now being
made, says the " Chicago Railroad Review," with an apparatus
for bituminous coal invented by J. T. Rich, of Philadelphia, who
puts into the fire-box a "dead-plate" extending from side to
side, sloping from a short distance beneath the door and then
turning down perpendicularly to the grate bars. Above is a
fire-brick arch extending from the back well forward, around
which the ascending flame must pass towards the front. Outside
the door is a hopper, constantly supplied with coal, which passes
in, as that already in the fire-box works down to the dead-plate.
A fire being started in the grate, cokes the coal on the dead-
plate ; and the heat is utilized by passing around the arch and
through the flues. As the coke, thus made, burns away, its heat
and gases, without smoke, passing through the flues, new coal
constantly works down and undergoes the same process. The
experiment thus far shows there is no doubt that the process will
result in almost entire freedom from smoke ; but the practical
question, whether steam can be made fast enough, _is not yet
decided. Journal Franklin Institute.

AERO-STEAM ENGINES.

The advocates, says the " Engineering," of what is known here
as the Warsop system claim that the application of that system to
a boiler and engine prevents the formation of incrustation, does
away with priming, and effects a considerable economy of fuel.
Now we have no wish to deny that under certain circumstances
results have been obtained which appear to warrant the above
claims, in those particular cases; but what we object to is, that
these results should be made the foundation of totally fallacious
arguments as to the value of the " aero-steam " system of work-
ing. It may be that the injection of heated air into a boiler is,
under certain circumstances, a good way of promoting the circu-
lation in that boiler, and thus preventing the evils by which a want
of proper circulation is attended ; but it by no means follows
from this that the injection of air is the best way of producing cir-
culation under all circumstances. On the contrary, until we have
clear evidence afforded to us that the injection of air so far im-
proves ths economic evaporation of, not a bad, but a thoroughly
good boiler, as to more than repay the cost of forcing in that air,
we shall regard the system merely as a means of counteracting
faults of construction which should not have any existence.

As with the boiler so with the engines. Non-condensing
engines having unjacketed cylinders, supplied with steam at

32 ANNUAL OF SCIENTIFIC DISCOVERY.

from 40 pounds to 50 pounds per square inch, and worked with
but little expansion, have in certain cases showed more econom-
ical results when worked with a mixture of steam and air than
when worked with steam alone in the ordinary way. But we
submit that such engines although we regret to say that large
numbers of them exist are not fair examples of steam machin-
ery, and that the credit to be derived from beating them in econ-
omy is but very small. Given an engine consuming say 8 pounds
or 10 pounds of coal per indicated horse-power per hour, and the
difficulty of making such alterations as will produce a more
economical result is not great. If the aero-steam engine is to
take a high position in the future, it must do far more than this ;
it must be proved to be more economical both as regards fuel and
maintenance than steam engines of thoroughly good construction,
such as are turned out by our leading makers ; and at present we
have but small hope that any such proof will be forthcoming. In
making this assertion, we have no wish to discourage Mr. War-
sop, Mr. Parker, or others, who, like them, are experimenting
on the use of steam and air in combination ; but what we desire
to point out is, that they would save themselves much use-
less present labor and expense, and future disappointment, if,
instead of contenting themselves with beating indifferent steam
engines, they would ascertain carefully and without prejudice
just what their respective systems can or cannot effect under the
best condition under which they can be applied. Engineers well
know that for a certain sum of money a steam engine can be con-
structed to develop a certain power with a certain consumption
of fuel. Let it be proved that by the adoption of the "aero-
steam " system there can be constructed for the same sum an
engine developing a greater power with the same consumption
of fuel, or the same power with a less consumption of fuel, and
without any increased cost for maintenance, and the value of
mixed steam and air engines will be established. Scientific
American.

THE FRICTION OF STEAM ENGINES.

If we did not believe that it is easy to say something new on a
subject which has been in a very peculiar sense worn threadbare
by the inventors of cylinder lubricators and steam greasers, this
article would never have been written. So far as we are aware,
all the information regarding the resistance of steam engines due
to friction is to be found in the circulars of inventors, one or two
papers read before engineering societies by the advocates of par-
ticular methods of lubricating engines, certain theoretical disqui-
sitions contained in text-books of mechanical science, and perhaps
a report or two in the "Journal of the Royal Agricultural
Society." It is almost needless to say that the subject is one of
very considerable importance ; but it may be worth while to bring
this importance home in a tangible form to the employer of steam
power. It may be stated, in pursuance of this object, that it by
no means follows "that an engine giving a very high indicated

MECHANICS AND USEFUL ARTS. 33

duty per pound of coal is really the most economical that a manu-
facturer can use, for the simple reason that the power required
merely to drive the engine may be so great as to render the sav-
ing in fuel valueless. A case in point suggests itself. An experi-
ment was made some time since with a compound engine, the
general particulars of which are before us. This engine was of
the annular type ; the large cylinder about 35 inches' diameter,
the inner cylinder about 15 inches, the stroke of both pistons was
the same, about 5 feet, the piston rods both laying hold of the
same crosshead, which was connected with an overhead beam.
The experiment consisted in shutting the steam off from the
inner cylinder and driving with the outer annular piston alone.
It was found that the engine, then indicating the same horse-
power as before, failed to drive the machinery at the proper
speed ; and it was not till the indicated horse-power was aug-
mented nearly 40 per cent, that the engine would do the work.
On permitting the steam to find its way to the inner c\*liiider as
before, the indicated horse-power fell to the original point, the
machinery being driven at the proper speed. We shall not pre-
tend to explain why this was the case. It is indeed difficult to
understand why the fact that the inner cylinder, though open to
the atmosphere, took no steam, should so enormously reduce the
effective power of the engine. The facts are as we have broadly
stated them, and there is no reason to think they would now want
explanation if engineers had in times past devoted a little atten-
tion to the study of the phenomena of friction in the steam
engine. We have no doubt whatever that many so-called eco-
nomical engines are doing very bad work indeed, nor that many
so-called wasteful engines, as far as coal is concerned, are giving
out a far higher duty than is generally believed. The entire
subject is wrapped up in mist, a mist which can only be dis-
pelled by careful experiments, extending over long periods, and
properly and fairly analyzed. That a few engineers have con-
ducted experiments on the friction of steam engines and other
machines is certain ; but it remains to accumulate in a single
volume the statistics which these gentlemen possess, and to put
them into a form which may render them generally useful. In
pursuance of this object we have for some time past been
accumulating data, as yet infinitely far from being complete. But
these data have, at all events, done this much, they have satis-
fied us that ordinary theories regarding friction in steam engines,
based on investigations concerning the coefficients of friction
between lubricated surfaces, apply most irregularly and imper-
fectly. In other words, there is no theory at present in exist-
ence which will enable us even approximately to predicate with
certainty what the loss of effect by friction in any given engine
may be. In certain cases, calculations made with this object will
correspond, with surprising exactitude, with the results obtained
through the indicator and dynamometer. But the engineer, rest-
ing satisfied with such occasional coincidences, is mistaken in Ids
views. In scores of other instances enormous discrepancies \vifl
be found to exist between theory and practice, the almost total

34 ANNUAL OF SCIENTIFIC DISCOVERY.

absence of frictional resistance in some engines contrasting
strangely with the expenditure of power absolutely wasted in
others. It is not the mere loss of fuel alone although that is
bad enough that has to be considered in dealing with this sub-
ject. We find engines unable to do their work overloaded and
worn out ; boilers burned and overtaxed ; grease and oil wasted ;
indeed, we go so far as to hold that every horse-power unneces-
sarily spent in overcoming the frictional resistance of a steam
engine costs three times as much as if it were spent in doing
useful work, and this without taking at all into account the fact
that useful work returns money, while what we may term the in-
ternal work of the steam engine returns none.

The difficulties which lie in the way of ascertaining by actual
experiment what the frictional resistance of an engine is are
very great, and to this cause no doubt is to be attributed the
greater portion of the existing ignorance of the subject. The
obstacles in the way are of two kinds. In the first place, it is
very difficult to put a dynamometer or brake on large engines,
whereby to ascertain their dut} r ; and, in the s&eond place, the
amount of friction varies not only in different engines, but in the
same engines, in a very extraordinary way. As regards the first
difficulty, we can, in the case of pumping engines, ascertain pre-
cisely how many foot-pounds of work an engine actually gives
out in the shape of useful effect, while the indicator shows the
work done on the piston ; but from these data it is impossible to
calculate engine friction exactly, because our calculations are
complicated by the greater or less efficiency of the pumps. It is
possible that nothing can be more deceptive than the results
obtained from pumping engines, and therefore we have no
hesitation in rejecting their aid in dealing with questions of
engine friction. Practically speaking the only generally available
test is the indicator, used with the engine light and the engine
loaded ; but diagrams taken thus do not account for the extra
friction due to the performance of work, though useful to some
extent in their way ; but no investigation of the qualities of an
engine can be regarded as complete unless the dynamometer is
used as well as the indicator.

As regards the variation in the loss by friction in the steam
engine, a very great deal might be said which we shall not
attempt to say now. It may induce others to experiment for
themselves, however, if we place a few facts curiously illustrative
of the peculiar phenomena of engine friction before our readers.
In one case we conducted the experiment personally ; for the
results of the other we are indebted to a gentleman who, in
superintending the replacement of ordinary boilers by the now
well-known Howard boiler, has occasion to indicate a very large
number of engines, and on whose accuracy we can rely with crr-
tainty. In the first experiment which w r e shall cite we found the
full power exerted by a rolling-null engine in the north of Eng-
land, -- where, it is unnecessary to specify, to be 291.5 horse.
This included the resistance due to fly weighing 30 tons, a bar-
mill with 2 pairs of rolls working on heavy orders, and the

MECHANICS AND USEFUL ARTS. 35

requisite gearing. Engine and mill empty required, according
to one set of diagrams, 74.8 horse-power to run them at the
working speed ; but, according to another set of diagrams, the
frictional resistance of engine and mill is less than 35 horse-power,
and all the diagrams were taken within a few hours. We cite
this case only to illustrate the difficulties engineers have to contend
with in endeavoring to estimate the friction of engines under
ordinary circumstances.

The other experiment is very interesting and curious as regards
results. The engine was a double cylinder traction engine, built
by Messrs. Howard, of Beckford. The cylinders are 8 inches 1
diameter and 12| inches' stroke. The engine shaft can be discon-
nected from all the rest of the machinery, so that the whole work
done by the steam consists in turning the crank shaft and over-
coming the friction of the bearings, pistons, etc. With 60 pounds
of steam in the boiler, the engine, making 190 revolutions, indi-
cated unloaded 2.64 horse-power. The engine Avas then set to
drive a brake loaded to 16 horse-power, the link being put in full
gear; under these conditions the engine indicated 22.55 horse-
poAver. The frictional resistance Avas therefore increased, by the
fact that the engine Avas HOAV doing Avork to 6.55 horse-power, or
to nearly 3 times that of the unloaded engine. This is all plain
sailing, but noAV comes a most remarkable fact. The throttle
valve Avas thrown full open, or nearly so, and the engine linked
up, that is, worked expansively at the same velocity, 190 revo-
lutions per minute. The load on the brake, etc., remaining abso-
lutely unaltered, any engineer Avould predict that, under these
circumstances, the result Avould be the same. Far from this being
the case, hoAvever, it Avas noAV found that, the effective Avork or
duty of the engine being unaltered, the indicated power was only
19.86 horse-power, so that the friction of the engine Avhen linked
up Avas only 3.86 horse-power, or little more than one-half that of
the engine Nvorking in full gear. Lest there should be any mis-
take about this, the brake Avas then loaded with 504 pounds.
With the link in full gear, the engine indicated 44.88 horse-poAver ;
the link Avas then put in the first notch, and the throttle valve
fully opened, everything else remaining unchanged, when the
power fell to 40.92 horse ; the frictional or internal resistance of
the engine in the latter case thus being 3.86 horse-powerless than
in the immediately preceding experiment. HOAV are these facts to
be accounted for? Is it that the varying strain on moving
surfaces in contact, due to the action of expanding steam, is
attended Avith less frictional resistance than is present when the
metals are under the steadier strain of non-expanding steam?
We shall not pretend to answer these questions. There are the
facts for the consideration of those interested.

Is it too much to hope that engineers, Avho have the opportu-
nity, Avill take up this subject and endeavor to throw light into
what is at present a A~ery dark and unexplored region of mechan-
ical engineering? We are convinced that the results Avould,
Avhen time and perseverance had multiplied data, be found of
very great value to those Avho desire to see the steam engine un-

30 ANNUAL OF SCIENTIFIC DISCOVERY.

dergo the real improvement of which it is still capable. Engi-
neer.

THE FAIRLIE ENGINE.

Mr. Robert Fairlie certainly deserves success, and we have
pleasure in believing that he is really commanding it. On two
recent occasions in the little "cabbage garden' 1 at Hatcham,
another of his great triumphs was exhibited in the trial of the
" Tarapaca," a double bogie locomotive of 60 tons' weight, coaled
and watered, destined for Peru. The experiments were wit-
nessed by some hundreds of eminent official and scientific men,
who were all in accord, in so far as we could hear, in their admi-
ration of the new engine, which for hours in succession performed
the feat, smoothly and with perfect success, of turning round the
oval in the gardens, the end curves being of only 50 feet radius.
The railway world has heard of Mr. Fail-lie's " Little Wonder" at
work upon the Festiniog Railway, and of the triumphs of the
"Progress" on the Brecon and Mertly Railway. The " Tara-
paca" may properly be designated the " Great Wonder " in the
adaptation of steam-power to locomotive purposes. As stated,
the engine is 60 tons' weight in working order, or 40 tons' weight
when empty ; the bunker-room is sufficient for 30 cwt. of fuel,
and the tank accommodation is for 2,200 gallons of water, which
should suffice for a 60 miles' run. The weight is equally distrib-
uted upon 12 wheels, in 2 groups of 6 each. The wheels in each
group are coupled together, so that nil the 12 are driving-wheels,
and the whole of the 60 tons is thus made available for adhe-
sion. The "Tarapaca" will have to work a gradient of 1 in 26
for 11 miles on the Iquiqui line in Peru, belonging to MM. Mon-
te ro Freres. The engine has 4 cylinders of 15 inches' diameter
and 20 inches' stroke. The wheels are 3 feet 6 inches in diameter,
and the brake-arrangement, very powerful, is applied to the 4
inner wheels of the 12. The force of the engine at the rails is
about 21,400 pounds, or 9 tons, on the level, at a speed of 12
miles an hour. The " Little Wonder" runs upon a gauge of 1
foot 11A inches; the " Tarapaca" is made for the ordinary 4 feet
Sh inches gauge. The Fairlie engine can double the capabilities of
any line, irrespective of gauge, its power being double that of
engines of the ordinary type. The Festiniog gauge is unduly
narrow, and' the ordinary 4 feet 8k inches gauge is wider than is
necessary to realize the maximum advantages of the Fairlie sys-
tem, which may be secured with a gauge of from 3 feet to 3 feet
6 inches. A 3-feet gauge line worked upon this system may be
made to carry as many passengers and as many tons of goods as
the broadest gauge line in existence, and it can be worked in the
ordinary manner, at a speed of from 40 to 45 miles an hour. The
dead weight on narrow-gauge lines is much less proportionately
than on broad-gauge lines. A wagon for a o-feet gauge, weigh-
ing 1 ton, will carry 3 tons of paying weight. The best form of
wagon on a 4 feet 8-i-inch gauge weighs from 3 to 5-i tons, and
carries from 5 to 10 tons, or about 1.90 ton per ton of wagon.

MECHANICS AND USEFUL ARTS. 37

The average load carried by merchandise wagons, exclusive of
coal, is about 10 cwt. paying weight. The load these wagons
ought to carry should be from 5 to 7 tons ; of paying load they
really carry but a twelfth of what they ought to do. If our goods
and mineral wagons were only a ton in weight, as they ought to
be, they would carry 3 tons of load, or 6 times the average load
now taken, and would reduce the dead weight from 4 to 1. A
railway company, that we forbear from naming, carries over its
line 126,000,000 tons per annum, out of which it takes payment
for only 15,000,000 tons of paying load. Fairlie's narrow-gauge
and 1-ton wagon system would reduce this gross tonnage one-
half, thus saving the company the cost of hauling 60,000,000 tons
per annum of dead weight. The experts who attended the
trials at Hatcham on the last two days were agreed as to the
entire absence of oscillation in the movements of the engine.
The ordinary locomotive, it is well known, increases its oscilla-
tion as it increases its speed, and ipso facto increases the power
and effect 'of the blows inflicted upon the rails. The oscillations
of the engines are communicated to the trains they draw, and
danger is thus increased. The Fairlie engine, it has been fully
demonstrated, runs more smoothly and faster without the pound-
ing of the rails caused by the engines of the ordinary type.
From all that we have seen of Mr. Fairlie's " Big" and " Little
Wonders " in his double bogie engines for any gauge, but prefer-
ably for a gauge of say 3 feet, we cannot doubt that the adoption
of his inventions would revolutionize railway working, and make
the difference, as regards railway property, that there is between
wasted money and lucrative investments. Ere long, notwith-
standing the vis inertias of the directorial mind, we have little
doubt that we will have English companies sharing with Russian,
Peruvian, and Welsh mine masters, in the benefits that Mr.
Fairlie and his double bogie system are ready to confer upon
them. An engine on the Fairlie principle has recently been com-
pleted in the United States, adapted to the roads of that country.
It is thus described by the "Springfield Republican:" "The
memory of that mythical divinity, the two-faced god, Janus, is
perpetuated in a double headed locomotive, built by Mason, of
Taunton, after a style invented by Robert Fairlie of England.
This ponderous and unique machine, which is to become the
property of the Boston and Albany Railroad, drew hither from
Worcester the other day 40 freight cars, half of which were
loaded. It would have drawn more had not the pump given
out, a defect easily remedied and by no means vital. It will
speedily be repaired, and the machine sent on a trial-trip up the
hills to Pittsfield immediately. This dual engine has 1 boiler
with 2 heads, and at each end rests on 6 drive-wheels. The cab
rests on the boiler, over the centre, where a lever lets on the
steam. The water-tanks and bunkers for coal are above the
boilers on each side of the cab. In going in one direction one-
halt' of the locomotive is going ahead and the other backing, and
the latter goes ahead when the steam is reversed, and the other
half backs. Thus the necessity of turn-tables is avoided, and it is

38 ANNUAL OF SCIENTIFIC DISCOVERT.

claimed that the same amount of steam in such an engine will
accomplish more than in one of the ordinary kinds." Van Nos-
trand^s Eng. Mag.

RAILWAY AXLES.

In a letter to the " Times" Sir Joseph TVhitworth makes a sug-
gestion relative to the construction of railway axles, which is
deserving of attention by the engineers of railways. He proposes
that a hole should be drilled through the centre of the axle,
throughout its length, thus opening up to inspection and exami-
nation that part of the material which, in the case of ordinary
manufacture, is most subject to unsoundness. The hole should
be about an inch in diameter, and, with suitable mechanical ar-
rangements, might be drilled at an average cost of about Is.
6d., per axle. With the outside turned and the inside thus
exposed to view, a serious flaw in an axle, which is only about
4^ inches in diameter, could hardly escape discovery. The plan,
he says, would also diminish the tendency of the axle to get
heated, and, by renewing the material near the neutral axis,
would, under the circumstances, reduce the internal strains, and
render the axle safer. Van Nostrand's Eny. Mag., Oct., 1870.

PUMPING ENGINES.

A set of the largest pumping engines yet made have just been
completed by Messrs. Gyime & Co., of the Essex Street Works,
Strand; they are to be erected in Denmark for some heavy
drainage works, to reclaim 20,000 acres of land for the jSIissum
Fjird Company, and of the most approved construction. The
manufacturers are confident that the engines and pumps will
raise 40,000 gallons, 178k tons, 12 feet high in one minute, which is
nearly 50 per cent, more than contracted for. The machinery
consists of a pair of engines, 4 feet apart from centre to centre,
coupled, with a pump on each side. The engines are 21 inches
cylinder expansive condensing, 21 inches' stroke, mahogany lagged,
running at 140 revolutions (490 feet piston speed) per minute,
and consuming 3 pounds per horse-power per hour; vacuum 27
inches. The pumps are constructed on Messrs. Gynne & Co.'s well-
known centrifugal principle, and are 42 inches' diameter in the
pipes. The same manufacturers will shortly have completed a
combined pumping engine for the Punjaub Railway, to discharge
1000 gallons per minute 60 feet high. Van Nostran&s Eng.
Mag.

*

ELASTIC TIRES FOR TRACTION ENGINES.

" Engineering" states that an interesting trial was recently car-
ried out between Rochester and Chatham of a 5-horse traction
engine constructed by Messrs. Aveling & Porter, of the former
place, and fitted with tires formed of India-rubber segments at-
tached to iron plates by a process patented by Messrs. L. Sterne

MECHANICS AND USEFUL ARTS. 39

& Co., Great Queen Street, Westminster, these plates being
bolted to the wheel-tire and further secured by iron rings. The
front pair of driving-wheels of the engine are 3 feet 6 inches in
diameter, and are fitted with India-rubber segments 12 inches
long, 4 inches wide, and 3 inches thick. The rear pair of driving-
wheels are 5 feet in diameter, and are fitted with India-rubber
segments 12 inches long, G inches wide, and 3 inches thick. The
rubber is firmly attached to one-fourth inch steel plates, which
are bolted on to the one-half inch wrought-iron tires, the seg-
ments being still further secured by five-eighths inch wrought-
iron rings placed on each side of the wheel.

The trial, which was conducted by Messrs. Aveling & Porter,
took place on Friday last in the presence of a number of govern-
ment officials, and some of our leading engineers. The engine
started from Messrs. Aveling's works, at Rochester, with 2
long 4 wheel lorries and a load of iron girders, giving a total
weight of about 13 tons. It proceeded at a pace of about 4 miles
an hour through the slippery streets of Rochester, travelling
steadily up Star Hill, which has a gradient of 1 in 12 for more than
300 yards. It made several sharp turnings round corners, the
radius of the path of travel being not more than 15 feet. With
one ordinary iron skid on the rear wheel of the hindmost lorrie, it
descended Rome lane, a steep falling grade, under complete
control. The rough and irregular stone causeway, the timber
bridge way of the Chatham dockyard, and the rough and broken
ground near the landing quay on the Medway, were all smoothly
and successfully traversed. The girders were landed on the quay
and the engine then returned to Rochester. The ground near
the landing quay is full of hillocks of cinder, clinker, stone,
bricks, scrap iron, etc., but, although the engine ran over all
these substances, not a cut nor permanent indent was to be found
afterwards in the India-rubber segments.

The great advantage of Messrs. Sterne's method of attaching
the India-rubber in segments over the solid ring is, that if a seg-
ment gets damaged it is easily and quickly removed and re-
placed by a spare segment at a moderate cost. The motion of
the engine during the run was easy, and the India-rubber readily
impressed itself into the inequalities of the roadways. To avoid
all possibility of slip in wet streets and on clay soils, Mr. Aveling
proposes to introduce steel staples or crossbars, so arranged as to
take the traction without neutralizing the benefit derived from
the elastic action of the rubber. There is no doubt a decided ad-
vantage in Messrs. Sterne's method of utilizing the India-rubber.
Traction engines with their wheels thus tired will prove useful
under the special local circumstances, such, for instance, as
where they have to traverse paved or very uneven roads. But
here, to our mind, the advantage of rubber-tired wheels ceases,
and we believe that the engine in question, or, in fact, any of
Messrs. Aveling & Porter's engines, would work as well without
as with this addition, and that in most cases the 130Z. or 140Z.
which these appliances cost could be more profitably expended
on the engine in other ways.

40 ANNUAL OF SCIENTIFIC DISCOVERY.

We may observe, in conclusion, that there is no fear of the
rubber parting from the plates to which it is attached by Sterne's
process. Its adhesion has been tested by Mr. Kirkaldy, who
found that a direct pull of 6,216 pounds, or 177| pounds per
square inch, was required to separate the two. In compression
the rubber segments stood 66| tons per square foot, returning to
their normal condition after the pressure was removed.

THE USE OF WIRE ROPE IN CIVIL AND MECHANICAL ENGI-
NEERING.

A marked feature of present mechanical progress is the in-
creasing use of wire rope in civil and mechanical engineering.
The world probably owes a greater debt to the late John A.
Roebling than to any other man connected with the introduction
of wire cables as a constructive material. It was he who, by his
scientific employment of this material, educated the public at
least the American public up to the full appreciation of its
value. From his labors and experiments the principal data upon
which other engineers now depend in the use of wire for con-
structive purposes have been chiefly obtained.

Now we find wire rope employed in almost every engineering
work. It constitutes an important part of modern ship-rigging.
It is used for hoisting, for towing boats, for bridges, for sus-
pended tramways, for propulsion of cars up heavy grades, and
even upon level surfaces. It is found to be the cheapest and most
efficient medium for the transmission of power to long distances.
Every year increases the number and extent of its applications.

Two of the most recent applications to which this material has
been put are, in our opinion, destined to prove equal in impor-
tance to any which have preceded them. We allude to the trans-
mission of motive power, and the tramway system invented by
Mr. Hodgson, of which several notices have recently appeared in
these columns.

The telo-dynamic cable system is, if we mistake not, destined
to a most brilliant future. This country affords a notable field for
its advantageous employment. Our mining districts are, many
of them, so situated that power can only be obtained in this man-
ner, or by the use of steam.

We do not entertain a doubt either that the wire-rope tramway
system will be found of vast benefit to our mineral districts. It
is simple, practical, and cheap, and has demonstrated its value as
a means of transporting ores and freights.

To what other uses wire rope may be destined it is impossible
at present to say, but the success which has attended its applica-
tions thus far encourages the belief that inventors and engineers
may still find it a valuable resource for purposes not yet thought
of, and in ways hitherto undiscovered. Scientific American.

THE WIRE-ROPE TRAMWAY AT BRIGHTON, ENGLAND.

The wire-rope transport system may be described as consisting
of an endless wire rope running over a series of pulleys earned

MECHANICS AND USEFUL ARTS. 41

by substantial posts which are ordinarily about 200 feet apart.
This rope passes at one end of the line round a drum, driven by
either steam, water, or even horse power in small farming oper-
ations, at a speed of from 4 to 8 miles per hour. The boxes in
which the load is carried are hung on the rope at the loading; end
by a wooden V-shaped saddle, about 14 inches long, linecf witli
leather, and having 4 small wheels, with a curved pendant, which
maintains the box in perfect equilibrium while travelling, and
most ingeniously, but simply, enables it to pass the supporting
posts and pulleys. By a sliding-ring arrangement the boxes or
buckets are easily emptied by tilting, without unshipping the
saddle from the rope. The boxes can be made to carry from 1
cwt. to 10 cwt., and the proportions of the line and the" loading
and discharging arrangements can be varied to suit any particular
requirement, ranging from 10 tons to 1,000 tons per diem. At
each end of the line are rails placed to catch the small wheels
attached to the saddles of the boxes, by which means the weight,
having acquired momentum, is lifted from the rope, and, thus
suspended from a fixed rail or platform, can be run to any point
for loading or emptying, and again run on to the rope for trans-
port, the succession being continuous, and the rope never requir-
ing to be stopped for loading and unloading.

Curves of sharp radius are easily passed, as well as steep
inclines, and its applicability to cross rivers, streams, and moun-
tains, or hilly districts, will be apparent at a glance, as the cost
of construction increases but little under such circumstances,
whilst that of a road or railroad is, perhaps, increased tenfold,
and the daily working cost doubled or trebled. The rope being
continuous, no power is lost on undulating ground, as the
descending loads help those ascending.

In the case of lines for heavv traffic, where a series of loads,

V

necessarily not less than 5 cwt. to 10 cwt. each, must be carried,
a pair of stationary supporting ropes, with an endless running
rope for the motive power, will be employed, but the method of
supporting, and the peculiar advantage of crossing almost any
nature of country with a goods line without much more engineer-
ing work or space than is necessary for fixing an electric tele-
graph, without bridges, without embankments, and without
masonry, exists equally in both branches of the system.

In the minor applications, such as short transport from mines
to railways, the landing or shipping of goods in harbors and
roadsteads, and the carriage of agricultural produce on farms,
some peculiar features of the system render it specially advan-
tageous. Amongst these are the facility with which power can
be transmitted by the rope and taken off at any required point
for mining or other purposes. In lines terminating on the sea-
board, or on great rivers, a manifest advantage is secured in the
facility lor taking goods direct to or from ships in harbor or road-
stead without transhipment into lighters.

Seen from a distance, the posts which carry the tramway wires
at Brighton might be mistaken for telegraph poles ; but a nearer
inspection reveals a second line of wires on the same level, and

42 ANNUAL OF SCIENTIFIC DISCOVERY.

upon these 2 wire-rope lines, supported on standards at intervals
varying from 300 feet to 1,000 feet apart, according to the re-
quirements of the ground, are suspended iron boxes for the
carriage of the goods, which boxes pass on noiselessly and stead-
ily, carried forward by the rope at the uniform rate of 5 miles
an hour, the time required for performing the entire circuit of
the line.

In laying out these 5 miles at Brighton, the opportunity has
been taken of exemplifj'ing the working of the system under
every variety of difficulty that could possibly present itself; thus
\ve have at one part an incline of 1 in 6, up and down which the
rope and boxes work with perfect facilit}', the descending weights
assisting those which are ascending; then there are, besides sev-
eral bends less acute, two instances of absolutely right angles
which are passed with the greatest ease. In some instances the
standards are carried to the height of 70 feet, to meet inequalities
of the ground, undulating and hilly country being more trying to
this system than craggy and mountainous, such as that for
which this plant is designed, and where, from the long reaches
taken, fewer posts will be required.

The line is rather over 5 miles long ; there are 112 posts, or
standards, in the whole length. These standards can either be
made of light angle and band iron neatly put together, as in the
present case, or of wood. The rope is made of charcoal iron, is
2 inches in circumference, each strand, as well as the centre of
the rope, having a hempen core, to secure ductility. The power
employed to drive the rope is a portable 16 horse-power engine.

Some of the spans are 600 feet and 900 feet in length, and in-
genuity has been shown in devising every possible mode of test-
ing the merits of this system of transport ; and we are bound to
record that all difficulties have been overcome with complete suc-
cess. The line is capable of delivering 240 tons per day of 10
hours, that is, 120 tons in each direction.

This tramway has been erected by Mr. Hodgson, the inventor,
at the request of some gentlemen with whom he was in negotia-
tion, for the supply of materials for a line 60 miles in length in
Ceylon.

It is intended to divide the proposed Ceylon line, of 60 miles,
into 5-mile sections, such as the one described, 1 engine work-
ing every 2 sections, and the boxes passing each section by
shunting arrangements, similar to those used at the termini, from
one section to another. The line in work will be open daily to
public inspection during the month of April, and is well worth a
visit. It is hardly likely that so efficient and economical a means
of transport will be for long exclusively confined, as at present,
to the conveyance of goods. For ourselves, we venture to con-
fidently predict an early adaptation of the principle of this in-
genious system to passenger traffic. Condensed from Scientific
Opinion.

MECHANICS AND USEFUL ARTS. 43

EXTRACT FROM THE REPORT OF COL. W. A. ROEBLING, CHIEF
ENGINEER OF THE N. Y. BRIDGE CO.

A boring made in 1867 showed gneiss rock at a depth of 96 feet
below high water. The strata penetrated consisted in the first
place of surface filling through alternate layers of hard pan and
boulders of trap embedded in sand and clay. Below 50 and 60
feet depth the material was so compact that the bore hole stood
without tubing for weeks. No necessity existed, therefore, for
going clown to rock; a depth of about 50 feet would suffice. But
the great desideratum to be attained was a uniform character of
the soil over the whole space of the foundation whatever the
depth might be. It is well known that the drift formation of
Long Island presents a great variety of strata in comparatively
short diagonal distances. Within a hundred or two feet on either
side of this foundation, there is no bottom, so to speak, and piles
are driven a great depth into mud ; whereas in the centre of our
foundation the depth of water was only a few feet ; the existing
ferry slip had been blasted out at a great expense, and to drive
an iron-shod pile even 2 feet into that material was the work of
hours. This hard material, however, occupied only a part of the
foundation, which comprises an area of 17,000 square feet. One-
third of the area towards the east was much softer in character ;
to meet the requirements of the case a heav}^ solid timber founda-
tion was decided upon, of sufficient thickness to act as a beam,
and having the requisite mass to insure a uniform settling. The
importance of a uniform foundation becomes evident at a glance
when we consider the size of the tower, weighing 35,000 tons,
with a height of 300 feet above the foundation upon which the
permanent pressure is 4 tons per square foot. In addition, the
buoyancy of the timber enables us to dispense with the screws
ordinarily used in towing a caisson.

In regard to durability, it is well known that timber immerse d
in salt water is imperishable, and to protect it against worms it is
merely necessary to sink it beneath the river bed. It at once
suggested itself to make the timber platform as far as possible a
part of the caisson. This has been done by making the roof of
the caisson a solid mass of timber, of 15 feet in thickness. The
object and purposes of a caisson in sinking a pneumatic founda-
tion is too well known to need any description here ; it is merely
a (.living-bell on a vast scale. It may well be said that, since the
unparalleled achievement of Captain Eads, at St. Louis, the word
caisson has become a household word among American engi-
neers.

The caisson of the East River Bridge is a large inverted vessel
or pan, resting bottom upwards, with strong sides. Into this air is
forced under a sufficient pressure to drive out the water. Entrance
is had to the large working-chamber, thus formed underneath,
through suitable shafts and air-locks. The material is taken out
through water-shafts, open above and below, and 2 supply-shafts
send down the material subsequently needed for filling up the air-
chamber.

44 ANNUAL OF SCIENTIFIC DISCOVERY.

The dimensions of the caisson are rectangular; length 168 feet,
width 102 feet, height 9 feet 6 inches. Thickness of roof 5 feet.
The sides form a V, and are 9 feet thick where they join the roof,
sloping down to a round edge. The inner slope of the V has an
angle of 45 degrees. The lowest part of the slope is formed by a
semicircular section casting, protected by a sheet of boiler plate,
which extends up 3 feet each side. A heavy oak sill rests on the
casting, and it consists of a stick nearly 2 feet square. The 3 suc-
ceeding courses are laid lengthwise, after that the alternate
courses are heading courses. The whole mass is thoroughly
bolted together by drift bolts, screw bolts, and wood-screw bolts.
In addition there are heavy angle irons uniting the V to the roof.
At the corners the courses of timber are halved into each other,
and strapped together for further security. The roof is composed
of 5 courses of 12-inch square j'ellow pine sticks, laid close
together, bolted sidewaj's and vertically, and having a set of
heavy bolts running through the 5 courses. The outer edge of
the caisson has a batter inward of 1 in 10 to facilitate its descent
into the ground.

To make the caisson air-tight, the seams were all thoroughly
caulked for a depth of 6 inches, inside and out. and in addition a
vast sheet of tin, unbroken throughout, extends over the whole
caisson, between the fourth and fifth course, and down the 4
sides to the shoe. The tin on the outside is further protected by
a sheeting of yellow pine. The space between the timbers was
filled with hot pitch. As air under pressure of 40 or 50 pounds
w r ill penetrate wood with ease, the inside of the air-chamber was
coated with an air-tight varnish, made of resin, minhaden oil, and
Spanish brown. The air-tightness up to the present time is quite
satisfactory, and only one-fifth of the air-pump on hand is suffi-
cient to keep the water out.

The yellow pine timber was selected specially for the purpose.
It came principally from Georgia and Florida, and much of it was
so pitchy that the sticks would not float. The average specific
gravity of all the timber was 48 degrees per cubic foot. Every
bolt-hole is bored with a large drift to ensure the hold of the
bolts. As the construction of the caisson proceeded, the iron
work of the water-shafts, air-lock-shafts, and supply-shafts was
put in.

The water-shafts, 2 in number, "are square shafts, three-eighths
boiler plate, properl} T stiffened by angle irons, and well secured to
the caisson. The} T are 7 feet by 6 feet 6 inches, and are open
above and below, the lower edge extending 20 inches below the
edge of the shoe. The water inside of them rises and falls with
the state of the tide outside. The material to be taken out is
shoved under the edge into the water-shaft by the laborers inside,
and is then taken out by the so-called clam-shell dredge of Morris
& Cumniings, of New York, the only known instrument which
possesses the precise action of the human hand in picking up
things. Any other arrangement for excavating in the shape of a
revolving dredge or a sand-pump was out of the question. The
air-shafts "are 3.0 feet in diameter, and extend simply through the

MECHANICS AND USEFUL ARTS. 45

timber on top of which the air-locks are placed. The supply-
shafts are 2 inches' timber, 21 inches' diameter, and of indefinite
length, they have a door at the bottom and one on the top with
an equalizing pipe. They are filled full of made air, and the
whole contents fall into the air-chamber below.

It was the original intention to have made the air-chamber
under the caisson one entire space without any divisions into
compartments, thus facilitating the excavation of the material.
Various considerations led to the abandonment of that view.
Since the caisson was to be launched like a ship, a certain num-
ber of launching-ways were required, and these required a stiff
frame from the launching-way up to the roof. Again, in the
boulder soil, only a few points of the edge would have rested and
supported the weight at any one time. But the chief point was
the rise and fall of the tides and their effect on the caisson. The
extreme rise and fall is 7 feet. If the inflated caisson is just
barely touching the ground at high water, it will press upon the
base with a force of 4,000 tons at low tide, all of which has to be
met by the strength of the shoe and the frames. And it is not
until the caisson is permanently righted down that the continuous
excavation can take place inside. The frames are proportioned
somewhat to the strains in launching, and form a heavy truss of
pine posts and stringers with 3-inch sheathing on each side, and
side-braces to the roof every C feet. The ends of the frames are
secured to the sides or the V by knees.

It was concluded to limit the pressure of the caisson during the
launch to 2^ tons per square foot of launching surface. This
required 7 ways in all, 2 under the edges and 5 under the frames.
The total launching weight of the caisson was 3,000 tons, con-
taining 111,000 cubic feet of timber and 250 tons of iron. It was
launched sideways, that is, with the long face of 168 feet by 14
feet 6 inches high 'facing the water. The ground-ways were laid
at an angle of 1 inch per foot, the caisson standing 50 feet back
from the end of the ways. To buoy up the forward end of the
caisson as it entered the water, and thus prevent its entire im-
mersion, a temporary water-tight compartment of 2-inch plank
was put in, one-third the distance across. It served its purpose
admirably. A full complement of wheel-barrows, crabs, and
winches were likewise stowed away in it. The ground-ways
consisted of 2 timbers, of 11 inches square each, bolted together
sideways. They were grooved like the guide of a planer, and
the upper launching-way fitted their grooves correspondingly.
The great danger of launching so large a mass on 7 ways consists
in the liability of one end going faster than the other, and thus
wedging the caisson fast on the ways. Only the outer ways were
provided with ribbands. They, however, proved superfluous to
accelerate the motion of the caisson as it entered the water, and
thus overcome the increasing resistance. The ways were laid
crowning to the amount of 18 inches in their length. The
launching-ways were likewise continued 10 feet back of the
caisson, and provided with shoes against the sides ; it was desir-
able that the rear edge of the caisson should leave the end of the

4G ANNUAL OF SCIENTIFIC DISCOVERT.

ground-ways uniformly, and not stick fast on one, a thing likely
to occur, since the ways stopped at the low-water line, and the
rear edge would iall at once into deep water. The above
arrangement answered the purpose.

On the 19th of March, 1870, the launch took place; in, every
respect a success. As soon as the last block was split out, the
caisson commenced to move. The impetus it had acquired in the
first part of its course proved sufficient to overcome the immense
resistance offered by the water. The caisson has daily been ris-
ing with every high tide and resting on the ground again at low
water, requiring most of the work inside to be don 13 at low water,
where the caisson is comparatively free from water. As the edge
does not readily sink into the hard soil, it is expected that there
will always be some water. Since the edge of the shoe is round-
ing, it allows the air to blow off before the level of the water
has reached the lowest limit. This is caused by any trifling agita-
tion in the level of the water inside, which gives the escaping air
a chance to establish an outgoing current before the head of water
inside becomes sufficiently great to overcome it.

By constantly building up on top the centre of gravity has been
raised considerablv, and the caisson is now in a condition of un-

V '

stable equilibrium, that is, it does no longer rise uniformly with
the rise of the tide. One end will remain on the ground and the
other rises as much more in proportion, and the more it rises the
more surface it presents to the upward pressure of the air on that
side, the general level of the water inside being governed by the
level of the highest point of the shore.

This rising of one end of the caisson is attended by another
phenomenon of imposing appearance. As the tide rises, and the
downward pressure of the caisson is about being overcome by the
increased tension of the air inside as well as the buoyancy of the
water outside, one end of the caisson will suddenly rise 6 inches
or more. The result is that for a few minutes the tension of the
air inside exceeds the head of water outside, and a tremendous
outward rush of air takes place under the shoe, carrying along a
column of water of hundreds of tons to a height of 60 feet at
times. This continues until a return wave inside of the caisson
checks it. These blow-offs are not felt to any extent by the men
inside, beyond the warning noise and momentary draft created.

The magazine of force contained in 170,000 cubic feet of com-
pressed air is so large that the loss of a few hundred tons is a
trifle. A system of pipes is put in the air-chamber for the pur-
pose of illuminating the air-chamber with calcium lights, a trial
of which has resulted favorably ; with moderate pressures, candles
answer very well. The first course of stone is now being
laid. Its weight, together with the concrete on top of the timber,
will probably suffice to ground the caisson permanently, and thus
permit the erection of setting derricks on the caisson. The stone
setting will then keep uniform pace with the excavation, and by
the time the desired point is reached the masonry is far above the
water level.

The stone used for these land courses, which will be perma-

MECHANICS AND USEFUL ARTS. 47

nently under water, is the Kingston limestone, furnished by
Noon and Madden. These stones have both beds cut, but the
sides and builds loft rough, with vertical quarry joints, the projec-
tions not exceeding 2 inches. The beds are exceptionally wide.
As the base of the masonry work resting on the timber is very
much larger than the section of masonry at the water level, it is
considered that this class of masonry is equally as good, and cer-
tainly far cheaper than regular dimension stone. All the stone
in any one course are cut to a uniform size. Above low water
granite will be used on the water face, and subsequently through-
out as freestone.

The first or corner-stone of the extensive pile of masonry to be
raised above the caisson, unlike as it was to ordinary affairs of
this kind, was a massive block of limestone from the quarry at
Kingston, Ulster Co., and in extent was 3 feet wide by 8 in
length, weighing about 5,800 pounds, or 165 pounds to the
cubic foot; and it is of this material that the foundation below
low-water mark will consist.

Additional borings are now being made for the New York tow6r.
The boring made 2 years since was 400 feet away from the act-
ual site of the tower. This one is directly on it. The same
stratum of 30 feet of the finest quicksand has been penetrated,
but boulders have been encountered at a depth of 80 feet, and the
indications are that rock will shortly be reached.

CONCRETE AND IRON BRIDGE.

A new bridge erected for Sir Shafto Adair, from the designs of

O

Mr. H. M. Eyton, of Ipswich, over the TVaveney, at Homers-
field, England, has been recently tested. In designing the bridge
advantage was taken of the principle of Messrs. Phillips' patent
fire-proof construction, -- a system in which all the iron-work is
completely embedded in Portland cement concrete. The bridge
has one arch of a clear span of 50 feet, with a rise of 5 feet 3
inches. The skeleton of the bridge is of iron, and this is en-
tirely filled in with Portland cement concrete, and rendered with
Portland cement, thus forming one continuous beam, getting
stronger every year, in addition to the iron skeleton, which is of
itself sufficient to do the ordinary statical work of the bridge ;
the weight of concrete alone is over 100 tons. The spandrels of
the bridge are relieved by a raised panel, and in the centre is a
casting of the Adair arms, taken from the old 3-arched brick
bridge. The first test applied was that of a 5-ton road roller
'drawn by 4 horses. This was passed across several times, and
not the least deflection was perceptible. Afterwards a heavy
wagon, laden with sacks of flour, weighing altogether 6 tons,
was passed over, and still, it is stated, no deflection could be
noticed.

BRIDGE OVER THE DNIEPER.

The railway bridge lately erected over the Dnieper, near

48 ANNUAL OF SCIENTIFIC DISCOVERY.

Kiew, is the largest work of the kind in Europe, being 3,503 feet
in length. Van Nost. Eng. Mag,

THE BROADWAY UNDERGROUND RAILWAY

Commences at the foundation lines of the splendid marble
building on the corner of Warren Street, and extends in a curve
directly down Broadway. The lower terminus is intended to be
at the South Ferry; but the present operating section only ex-
tends a little below the City Hall, near to the north end of the
new post-office premises, a distance of some 300 feet.

The bed of the railway is 21 feet below the surface of Broad-
way, and the diameter of the tunnel 9 feet. The passenger car
is about the same size as the ordinary street cars. It is very
tastefully fitted up, brilliantly lighted, and has seats for 22 per-
sons. It is propelled by the atmospheric system ; that is to say,
by means of a strong blast of air which is supplied to the tunnel
by a gigantic blowing-machine.

The whole operation is described as being exceedingly simple
and effective. The visitor enters at the corner of Broadway and
Warren Street, descends a few steps to the waiting-room, an
elegant apartment, but wholly under ground, at the end of
which is seen the mouth of the tunnel and the car. On taking
seats in the car, the conductor closes one of the doors and
touches a telegraph signal, when the car immediately begins to
move around the curve, and travels rapidly down Broadway. On
reaching the lower end of the tunnel, the car moves instantly
back again to Warren Street, then down Broadway again, and so
on. The air is so clastic that the changes of motion in the car are
effected with exceeding gentleness, and are almost imperceptible
to the visitor.

The car is run by telegraph ; that is to say, the wheels of the
car, at certain points on the route, press a telegraph key, sending
a signal to the engineer, who turns a valve and thus reverses the
air-current, without stoppage of the machinery.

The aeolor, or blowing-machine, by which the air-current is
produced, consists of a pair of great wings, geared together, and
turned by steam. It is capable of discharging 1 100,000 cubic feet
of air per minute, or enough to fill the interior of 3 3-story city
dwelling-houses.

The south end of the tunnel is provided with a lateral air-shaft,
which opens in the grass-plot of the City Hall Park. The air-cur-
rent thus traverses through and through the tunnel, the atmos-
phere of which is thus kept pure and fresh.

During the construction of the tunnel the entire travel of Broad-
way, omnibuses, carts, hacks, and other vehicles, in endless pro-
cession, passed on as usual, directly over the heads of the work-
men. They were safely protected within the sides of an immense
boring-machine, by which the bowels of the street were excavated.
It is pushed forward into the earth by means of powerful hy-
draulic rams ; and as fast as it advances the masonry is built up
within its rear.

MECHANICS AND USEFUL ARTS. 49

The works of the Broadway Underground Railroad, taken
altogether, are of a most interesting: nature, well worthy of ex-
amination. The general plan of the Company is to lay a double
line of tubes from the South Ferry, under Broadway, the entire
length of the island, with a branch at Union Square, under Fourth
Avenue, to Harlem River. Such a road would have capacity for
carrying 40,000 passengers per hour.

ROTARY PUDDLING FURNACES.

A number of puddlers, of this character, have, for some time,
been in successful operation at the Cincinnati Railway Iron Works,
and have attracted considerable local attention.

The machine puddlers dispense with the hand labor of the
usual furnaces, performing the same duty by steam " power.
Those at present in operation are making puddled balls of from
650 to 700 pounds in weight; and others, of greater capacity, are
in process of construction. Samuel Danks, of that city, is the
inventor.

SUSPENSION BRIDGE AT PITTSBURGH, PA.

This bridge crosses the Alleghany about half a mile above its
junction with the Monongahela, both of which streams, when
united, form the Ohio. The town of Pittsburgh is situated on the
promontory made by the convergence of these two rivers, and
has, with its suburbs, a population of about 200,000. The dis-
tance between the abutments of the bridge is 1,037 feet 5 inches,
being divided into 2 main spans of 344 feet 6 inches each, one-
half span of 117 feet 5 inches, and a second half span of 171 feet.
4 wire cables carry the structure ; the 2 outer ones incline out-
wards from the towers, and. the 2 inner inwards, to give stability
to the bridge. The lighter cables which carry the footway are
each 4j| inches' diameter, that of the others being 7 inches. The
roadway is 20 feet wide, and the footways each 10 feet. The
cables are attached to bell-cranks at the towers, instead of by
saddles placed upon rollers, a by no means satisfactory
arrangement, the vibration of the bridge being increased per-
ceptibly by the lightest passing load. The towers are about 45
feet high. They are of cast iron, and of an ornate character, the
weight they support being entirely carried by the 4 inclined col-
umns, which are braced together by latticed castings. Scientific
American.

A STEEP RAILWAY.

A railway has been constructed in Pittsburgh, Pennsylvania, to
carry passengers to and from the top of what is known as Coal
Hill, which overlooks the city and the country around to a great
distance.

The plane is located 250 feet west of the Monongahela suspen-
sion bridge. The roadway starting from Carson Street crosses the

50 ANNUAL OF SCIENTIFIC DISCOVERY.

Pan Handle Railroad, and reaches the face of the hill (which at
this point is 90 feet above the level of the Pan Handle Railroad
track) by means of an iron bridge 160 feet long. This bridge is
supported by 10-inch columns, made of wrought iron a quarter of
an inch thick. "The vertical height of the hill at this point is 330
feet, giving the plane a length of 650 feet, and an inclination of

35 degrees. The roadway consists of 2 tracks, each 5-feet gauge,
with 2 cars, one ascending while the other descends. The
cross-ties on the iron bridge are yellow pine, 7 feet by 7 feet.
The stringers are also yellow pine, 6 by 8 feet, and the ties on the
balance of the track 8 feet by 8 feet. A pine railing runs from
the base to the top of the incline. It is 3 feet high, and quite
fancy. It is to be painted probably white. The rails are of
the " T " pattern, and substantially fastened to the stringers.

The cars are to be hauled up by a wire rope, and are provided
with a safety-cable, which runs idly except in case of the breakage
of the principal rope, when the drum about which the safety-
cable winds is held by means of a brake, thus preventing the
accidental descent of a car. Scientific American.

THE NEW TUNNEL UNDER THE THAMES.

The new tunnel does not detract from the merits of Brunei's
great achievement in constructing the renowned passage between
Rotherhithe and Wapping, but it is as great a wonder in its way,
and in several respects offers a marked contrast. The old tunnel
brickwork is 38 feet wide by 22k feet high ; the new tunnel con-
sists of an iron tube about 8 feet diameter over all. The old tun-
nel was worked by a shield weighing 120 tons, accommodating

36 workmen ; the new tunnel has been driven by a shield weigh-
ing 2 tons, and accommodating at most 3 workmen at a time.
The old tunnel was 5 times tilled by irruptions from the river;
in the construction of the new tunnel the water encountered
might at almost any time have been gathered in a stable pail.
18 years elapsed between the commencement and the completion
of the works in one case ; less than a year has sufficed for the
execution of the works in the other. The descending shafts of
the one were 84 feet deep and 50 feet diameter ; of the other they
are under 60 feet deep and 10 feet diameter. The cost of the one
was over 600,000 ; of the other it has been under 20,000.

At the Tower Hill shaft we found the lift in which passengers
are to ascend and descend fitted and at work. It is an iron
chamber nearty cubical in shape, and large enough to accommo-
date 7 or 8 persons comfortably. The entrance is by a pair of
sliding doors. Guide-rods are attached to opposite sides of the
shaft, and corresponding grooved rollers are fixed to the sides of
the lift. The lift is balanced by a large cast-iron weight with an
open centre to admit of its being loaded in accordance with the
number of passengers that have to be raised or lowered. There
is a continuous connection above and below between the lift and
the balance weight by chains and wire ropes, calculated for 50
times the strain that can ever be put upon them. These pass

MECHANICS AND USEFUL ARTS. 51

over pulleys at the top and bottom of the shaft. The balance
weight works also in a pair of guide-rods. Mr. Barlow has de-
signed a brake attached to the roof of the lift, and acted on by a
powerful double-handed screw on the inside of the roof. The
effect of applying the brake is to release 2 arms which clip the
guiding-rods on each side, and effectually stop the descent in a
few feet. At the bottom of the shafts, and under the level of the
subway, are engine-rooms and coke-cellars. The engines at each
end are of 4 horse-power, and these will at any time supply more
than sufficient power for all purposes. The lifts are adjusted at
each end with their doorways inwards towards the subway. On
emerging at the bottom of the shafts, the passengers enter a
chamber, which constitutes the " station," at and from which the
one omnibus, which constitutes the entire "rolling stock " in use
at one time, arrives and departs. There is space in these wait-
ing-rooms for a seat along each side. We found the workmen at
the Tower Hill shaft busy with the fittings and finishings of this
chamber, and passing thence we entered the subway and pro-
ceeded through its entire length under excellent guidance.
Ordinary passengers, when the tunnel has been opened for traffic,
will not realize the curious sensation and experience of a passen-
ger through on foot, from the noises overhead, on and near the
river, so distinctly heard in the subway, which is air-tight as well
as water-tight. Arrived at the Tooley Street end, we found the
waiting-room occupied by the light iron omnibus in which pas-
sengers are to be conveyed. The vehicle, seated for 14 passen-
gers, is tolerably roomy as regards width, but is necessarily
rather low in the roof. The seats, cushioned and with stuffed
backs, are placed lengthways, the entrances being at the ends.
The wheels are 16 inches 1 diameter, and at each end of the car-
riage a powerful lever brake is fitted, to be worked by the con-
ductor with his foot. The service will of course be of the shuttle
character, the 2 halves of the omnibus being duplicates, the front
end of the vehicle in one journey being the hinder end in the
return. The gauge of the rails is 2 feet 6 inches, and the descent
from each end to the centre of the subway is by a gradient of 1 in
30. We found the works connected with the Tooley Street shaft
rapidly approaching completion, but not quite so near it as those
at the north end : the' subway itself may be pronounced finished,
and the omnibus fit to take the road at any moment.

The omnibus will be hauled by a wire rope running upon a
horizontal pulley-wheel fitted between the rails at one end, and
passing round a vertical pulley-wheel at the other.

THE KANSAS AND MISSOURI BRIDGE.

This bridge was designed and located by Mr. W. W. Wright,
Engineer in Chief, and is being constructed under his supervis-
ion. The superstructure is to be of wrought iron, resting upon
cast-iron piers, formed of large pneumatic piles sunk to a bear-
ing on solid rock. These piles are 8k feet outside diameter, with

52 ANNUAL OF SCIENTIFIC DISCOVERY.

a thickness 1| inches, and weigh about 1 ton to the square foot in
height. They are manufactured in sections of 10 feet in length,
with inside flanges at both ends to enable them to be connected
together during the process of sinking, and thus form a continu-
ous cylinder from foundation to bridge-seat. These columns will
be filled with cement masonry and concrete from the bottom to
an elevation 10 feet above high-water line. There will be 2 piers
of this kind in the river, and 1 on the eastern shore. The west-
ern end of the bridge will rest on a stone abutment. The 3
spans thus formed will be each 340 feet in length, and the bot-
tom of the lower chord will be 50 feet above extreme high water,
thus leaving ample space between the piers and sufficient height
above the surface of water for steamboats to pass at any stage of
the river. The approach to the bridge at the eastern end will
consist of a substantial trestle work 1,500 feet long, connecting
with an earth embankment extending 2,500 feet further.

LATTICE GIRDERS AND SOLID PLATES.

The English magazines have of late been devoting much space
to a discussion of the relative merits of solid plates and lattice
girders, and though the question is certainly an important one,
entailing, as it does, almost a revolution in the methods of con-
struction, in case lattice girders possess all the advantages their
advocates claim, yet the topic is still discussed, and the solution
of this problem in mechanics seems nearly as far off as ever.

Those who rank among the more modern class of thinkers, who
first theorize and then demonstrate, claim that the lattice will, for
the same amount of material, sustain greater strains and endure
shocks much better than a homogeneous plate, and the argument
sustaining this claim is based chiefly upon the fact that iron will
resist a greater force, applied in the direction of its fibres, than
when across them, and it is claimed that mathematical analysis
will render possible such an arrangement of the parts of the
lattice that all, or nearly all, the strain will be in the direction of
the grain or fibre of the iron.

Now, if we admit, what we certainly cannot prove to be false,
that the engineer can, from pure theoiy and by the aid of mathe-
matics, so place and arrange the parts of a girder that the strains
will be in the direction of the fibre, and proportionate to the size
of the pieces, we can draw a strong comparison in favor of open
or lattice work.

No scientific man will deny the fact that a wire rope is both
lighter and stronger than an iron rod of the same diameter, or, if
he claim the privilege of comparing the actual sectional area,
taking the sum of the sectional areas of the individual wires, we
can still claim greater strength for the rope upon the ground of
more perfect structure, as proved by experiment, the weight, of
course, being the same, or nearly the same, in either case. Eng-
lish bar iron will resist about 60,000 pounds' tensile strain to the
square inch, before parting, while wrought iron will resist over
100,000 pounds for the same actual area. Now, compare the

MECHANICS AND USEFUL ARTS. 53

lattice and plate in the same way. The plate corresponds to the
solid bar and the lattice to the wire rope, and the openings to the
space between the wire. Here we have undoubtedly so placed
the direction of the strain that it is all with the fibres, and find
that we have the proportion of 10 to 6 in favor of the structure
composed of several separate pieces.

Now, though this is perhaps an extreme case, and the argu-
ment only one by analogy, yet, while perhaps the same propor-
tions would not exist between the degrees of resistance afforded
by lattice girders and solid iron plates as between the different
qualities of iron, from the superiority of construction obtained
in the former, the reasoning will apply most forcibly. It will
probably not be denied that the superiority of construction claimed
really does exist, and this one argument is, therefore, taken
alone, convincing.

But, after all, the matter of the relative strength of the
material in different cases is really of less importance than is
the apparently simple problem of fastening the parts together.
If, after being properly arranged, the parts of the lattice can
be so fastened together that each piece will do its entire
duty without unduly straining its neighbor, there can exist
no doubt that the lattice will be stronger than the iron plate
girder, with its present form and arrangement; but, on the con-
trary, could the plate be placed in such a way as to be of equal
strength at all points, without increasing the weight of the struct-
ure, the iron plate would certainly rival the weak forms of lattice
as now constructed. Upon the ground that this perfect construc-
tion cannot be obtained in a solid plate, the advocates of the lat-
tice girders rest their claim, and it would seem that their as-
sertions cannot, as regards this point, be readily controverted.
American Builder.

SINKING SCREW PILES.

A machine has been lately designed by an English firm, at the
request of PI. Lee Smith, Esq., chief engineer for the Punjaub
Northern Railway, for screwing down piles to be used in con-
structing bridges and flood openings on that line of railway.
This machine consists of a wrought-iron under-carriage mounted
upon wheels of 5 feet 6 inches gauge, and carrying a vertical
boiler at one end. A strong cast-iron beam in the centre carries
a cylinder in which works a ram, to the top of which a strong cross-
beam is bolted which carries the machinery for operating on the
piles. This consists of a horizontal steam engine bolted to the
side of the cross-beam, and driving a pinion and train of spur and
bevel wheels which impart motion to two large horizontal wheels
carried in bearings at each end of the cross-beam. A friction
clutch is carried in the centre of each of the wheels, through the
boss of which the shaft of the pile to be screwed is passed. The
shafts are rolled with feathers or ribs on each side, which, passing
through corresponding recesses or key ways formed in the boss of
the friction clutch, form the means of imparting motion from the
horizontal wheels to the piles ; steam is brought from, the boiler,

5*

54 ANNUAL OF SCIENTIFIC DISCOVERY.

through the centre of the ram and cylinder which carries the

vi ^

cross-beam, by means of a telescope joint, which allows the ram
to be raised without interfering with the steam pipe ; and a small
donkey engine is provided which can pump from a tank situated
between the frame, either into the boiler or into the cylinder
under the rani which carries the cross-beam. When the machine
is at work the cross-beam, is held firmly by means of cotter bolts
to the frame. The modus operand! is as follows: A temporary
road being laid on the centre line of the proposed structure, piles
are pitched by passing the shafts through the wheels on each side
of the machine, and keying them into screws which are placed in
a small hole excavated to receive them. The engine is then set
to work, and the piles screwed down as far as possible. The cot-
ters holding the cross-beam are then removed, and it is raised by
the donkey engine pumping into the cylinder of the machine, and
lifted olf the piles. The machine is then moved forward to the
centre line of the next pile, and the operation takes place as
before. Journal Franklin Institute.

TRANSFORMATION OF CAST IRON.

"Transformation of Cast Iron, AVrought Iron, and Steel, by
means of the Vapors of Alkaline Metals," such is the title of a
patent taken in France, by MM. Charles Girard and Jules Poulain
(date 17th August, 1869, No. 86,784), the particulars of which
we extract from our excellent contemporary, the " Moniteur Sci-
entifique :"

" In order to cause the vapors of sodium and potassium to act
on cast iron in fusion, we heat one of the former metals in an iron
retort to 392 or 482 under a pressure of 5 or 6 atmospheres.
When this heat is reached we direct the vapor thus obtained into
the heart of the iron in fusion ; the mass swells, and an alloy of
the iron is the result. These alloys, although very hard, are
malleable, and may be forged and welded. They oxidize rapidly in
air or water, and are easily decomposed if a current of air, steam,
or carbonic oxide is injected into them when in" fusion. By these
compound effects of the vapor of sodium and of air, for example,
the whole of the metalloids in the iron are attacked, and the final
result is pure wrought iron, that can be hammered and Avelded with
ease. Under certain circumstances the metal resulting from the
operation may present the properties of steel. Finally, to ^facili-
tate the production of the metallic vapors, carburets, rich in hy-
drogen, may be added to the sodium or potassium in the retort.

"In place of sodium or potassium an alloy of the two may be
used; as, for instance, one composed of 4 parts of potassium
(melting at 122) and 2.5 parts of sodium (melting at 194).
This mixture, which has the appearance and consistency of mer-
cury, has its point of solidification at 47.4, and is consequently
liquid at ordinary temperatures. It is prepared under naphtha.

** It has been remarked that, besides the direct transformation
of cast into wrought iron or steel, by means of the metals, their
action produces other advantages ; they allow of the employment

MECHANICS AND USEFUL ARTS. 55

of iron castings, which, although containing manganese, can-
not be converted by the Bessemer process, on account of the
quantity of carbon, sulphur, or phosphorus which they contain.
It is, in fact, now proved that the Bessemer process, far from
eliminating the sulphur and phosphorus, tends rather to augment
the proportion of these metalloids.

" The cast irons known as cJiaudes, and which contain silicium
and magnesium, owe a part of their superiority to the calorific
power of the silicium (7,800), the produce of the oxidation of
which, silica, requires but little heat to disengage it, so that the
liquefaction becomes more complete. On the other hand, carbon,
under the same conditions, gives rise to the disengagement of
masses of sparks produced by the gases, carbonic acid and car-
bonic oxide, which traverse the mass ; these take from the molten,
matter a considerable quantity of caloric, and are thus unfavorable
to liquefaction.

"In our process this latter inconvenience is partly dispelled ;
for the gases produced by the combustion of the carbon, sulphur,
and phosphorus, combining with the soda or potash, are mechani-
cally carried through the mass of metal by the oxidation of the
sodium of potassium. The direct action of the sodium or potas-
sium, in the form of vapor, on the melted iron, may be replaced
by adding to the mixture of ore, fuel, and flux, either chloride of
sodium, carbonate of soda, a corresponding salt of potash, or a
mixture of these.

" Acting thus on any given ore, and using coke or coal as fuel,
a result analogous to that obtained with charcoal under the ordi-
nary system is obtained. We must add, however, that in the
former case the current of hot or cold air should be longer main-
tained than when charcoal is used ; this prolonged application of
hot or cold air in the blast furnace may present inconvenience,
which may be avoided by directing the alloys of cast iron with
sodium or potassium into a converter, in which they may undergo
the final action of the current of air ; with this process the work-
ing of the blast furnace is the same as in ordinary cases.

"We arrive practically at an assimilation of the coke or coal
with alkaline salts corresponding to those furnished by wood
charcoal, either by watering the fuel with the alkaline solutions
above mentioned, and then allowing it to dry in sheds ; or, lastly,
by pouring a concentrated solution of the various salts on the fuel
or the ore at the moment of charging the furnace. We intend to con-
tinue our experiments on the alloys and combinations of sodium
and potassium with most of the other metals." Scientific Ameri-
can.

IMPROVEMENT IN ENAMELLING IRON AND STEEL.

The process of Benjamin Baugh, of Chadwick, England, of
enamelling iron and steel, patented recently in the United States,
is as follows :

Lay upon the surface of the. plate of the metal to be enamelled

5G ANNUAL OF SCIENTIFIC DISCOVERS".

a uniform ground, of any color required to produce the intended
design; as, for instance, a name-plate, or tablet, with the ground
white and the inscription in blue. The white ground, having
been fused on in the melting-furnace and allowed to cool, there is
then applied, with a brush evenly over the whole surface, a coat-
ing of blue enamel, the materials of which are finely levigated
and mixed with gum-Arabic and water, or other mucilage, to form
a paste of slightly adherent properties.

When dry, a stencil of the inscription, or of each letter sep-
arately, is laid on, and the enamel paste is removed from the
parts which are unprotected by the stencil, by the application of
a stiff brush, leaving the ground clean, except the letters. The
plate is then again subjected to heat, whereby the paste, which is
fusible at a lower temperature than the ground previously laid,
becomes permanently fixed upon it.

The mechanical removal, by means of a brush, enables very
delicate lines to be formed through the paste, to expose the en-
amel ground, and admits of the use of ornaments having sharp
angles and minute points and details to be distinctly and per-
fectly rendered.

The ground may be dark, and of any color, as well as of the
kind described, and the subsequent coat of a lighter color; as,
for instance, the ground may be of blue and the inscription white,
and a succession of colors may be given to produce a variously
colored design, by the same method.

The inscription or design may be cut out in the stencil, and the
ground thereby exposed be removed by the brush, instead of the
surrounding parts, with a like effect, it being left to the choice of
the designer whether this process be followed, or that previously
described.

The stencils are formed of very thin sheet metal (or even of
paper, where they require to be used but a few times), which, by
their flexibility, lie more closely in contact with the surface, and
leave the lines" and margins of the figures perfect, while they con-
form to convex and irregular surfaces.

He combines with the method described the use of artistic
graphic representations, such as views, portraits, or groups,
thereby producing metal tablets decorated in enamel, in a man-
ner adapted to architectural purposes, as the finishing of interiors,
panels for cabinet work, etc. Such designs are produced upon
stone in the usual lithographic manner, and printed in successive
impressions upon paper prepared for transferring, by having its
surface coated with gum-Arabic, or other substance that is soluble
in water, mineral colors and fluxes being used, which are -adapted
to fuse under heat, and combine to form the picture in enamel
of appropriate colors.

The enamel ground having been fused on, as previously de-
scribed, for stencilling, it is covered with copal or other suitable
varnish, and the face of the prepared picture is laid upon it and
pressed, to insure adhesion of all parts, when the paper is re-
moved by wetting, as is ordinarily clone in transferring prints.
The plate is then subjected to heat until the colors of the picture

MECHANICS AND USEFUL ARTS. 57

are fused, and become incorporated with the previously enamelled
surface.

IMPROVED APPLIANCES FOR THE PRODUCTION OF HEAVY

FORGINGS.

The forging of iron in large masses is a subject of so much
importance to our engineering industry that it needs little apology
for its introduction to the mechanical section of the British Asso-
ciation, and any improvement in the machinery or appliances for
the more economical or rapid manufacture of large masses of
wrought iron, or for any improvement in quality, must be of great
interest to all manufacturers where such products are needed.

These improvements, in the manufacture of large forgings, I
intend to class under 3 heads. I propose simply to mention a
few. prominent facts very briefly, but shall be glad to answer
any inquiries that members may require further information
about. 1. Improved heating by Siemens' regenerative gas fur-
nace. 2. Facilities for handling and moving large masses of
wrought iron from the furnace to the hammer, and for moving
them under the hammer. 3. Improved hammers, with a clean,
unfettered fall, and with such width of standards as to give the
workman all the comfort and convenience possible in executing
the necessary operations of shaping, forging, and cutting the
material to the required form.

1st. Improved heating by Siemens' regenerative gas furnace.
It is generally admitted that iron in large masses is greatly dete-
riorated by long exposure to high temperatures, and that a crys-
talline structure is developed in consequence of such a form and
nature as to detract in a very great degree from the strength of
the material. It must, therefore, be admitted that furnaces, such
as those of Siemens, which produce the most intense heat in the
shortest possible time, must cause less deterioration to the product
in hand than those which are slower in operation ; but a more im-
portant item in this consideration is that the facilities given for
regulating the admission of gas and air in a neutral flame can be
produced ; and, in consequence, the iron may be preserved from
that burning and oxidation which are the cause of the formation
of those large facets or crystals which weaken many wrought-
iron structures of large size to such an immense extent.

Another improvement, from these furnaces where the iron is
prepared from the pig, is, that the gas furnaces do not bring over
the large amounts of unconsumed ash or debris from the coal
which is usually deposited on the body of the iron made in the
ordinary puddling furnace, and, in consequence, the iron is more
free from those specks and flaws which are so observable in or-
dinary iron, and which produce the heating and galling so com-
mon in large forgings, as heretofore made, and which cause the
chief torment of the practical marine engineer.

Perhaps the greatest advantage which the Siemens' furnace
offers is in the manufacture of forgings of puddled steel, from the
facility in which the flame of the furnace may be regulated, first,

58 ANNUAL OF SCIENTIFIC DISCOVERY.

in the puddling process, and, secondly, in the heating of the
puddled steel masses. In furnaces of ordinary construction a
constant deterioration of the puddled steel must necessarily take
place from the free oxj 7 gen present in the furnace ; but in the
Siemens' furnace the gases may be so regulated that a neutral
flame is produced, and, consequently, the steel mass is heated
without deterioration.

I will not now enter into the question of economy of fuel, as
this has been often discussed at meetings of mechanical engi-
neers ; nor will it be necessary to enlarge upon the great advan-
tage, especially in large towns, of the absence of smoke, which
has been hitherto thought a necessary nuisance in all branches of
the iron manufacture.

2d. The second improvement which I would wish to mention
is improved facilities for handling and moving these large masses
of iron when heated as above described, which is effected by hy-
draulic cranes and machinery of sufficient power to move these
large masses almost instantaneously either from the furnace to
the hammer, or vice versa, to raise and lower the load, or to in-
crease or decrease the distance of the load from the centre of the
crane.

The truth of the old adage, of striking when the iron is hot,
will prevent any necessity of dwelling upon the advantage of
rapidity of movement in dealing with large heated masses of iron.
After the pieces of iron have been heated in the manner de-
scribed, and when the machinery shown has brought the forging
to the hammer, it is necessary that the instrument should be of
the most approved description to cope with the material under
operation in the best and quickest manner, and with the greatest
possible comfort to the workman employed at the work desig-
nated. Hammers that are described as suspended are employed ;
they are carried upon w rough t-iron girders, of 20 feet span,
which gives the hammer-man such room for his operation, and
such freedom from any obstacle to his work, as have seldom, if
ever, been accorded before, and so much room to the rear is re-
served that shafts 50 feet or GO feet long could readily be made
without any inconvenience. Abstract of a paper read by Lieut.-
Colonel Clay, of the Birkenhead Forge, before the British Association.

CORROSION OF IRON GAS AND WATER MAINS.

In an editorial on this subject the " Gaslight Journal" remarks
that the deposits which form in the interior of iron water mains
cause serious annoyance and loss to many of our water compa-
nies. To so great a degree does this evil extend, that strenuous
efforts are being made to substitute some other material for iron,
which shall possess all its valuable qualities, and at the same
time be free from liability to corrosion, and consequent obstruc-
tion. The appearance of this internal deposit is very singular
and assumes various modifications. Sometimes the corrosion is
of a uniform thickness, and appears to attack the surface of the
iron evenly, while at others the whole diameter of the pipe is

MECHANICS AND USEFUL ARTS. 59

jagged with tubercles of various sizes and shapes, occurring at
irregular intervals.

Tlius far no satisfactory explanation has been given of the
causes of this peculiar deposit. That it is a species of oxidation
is very clear, since the mass formed has all the external character-
istics of iron-rust ; but why it should assume such peculiar physi-
cal properties, and present a configuration so unlike the outward
forms of other oxidation, has not yet been satisfactorily ex-
plained.

The effect of this incrustation is obviously very disastrous to
the economical distribution of water, as the diameter of the mains
is so much diminished as to reduce their capacity to that of much
smaller calibre than they were originally constructed. In addi-
tion to this, the strength of the pipe is much impaired by this
process of oxidation, and it is rendered much less able to bear
sudden concussions and heavy pressure than previous to the
formation of the deposit. This must be apparent to all intelli-
gent observers, for it is at the expense of the iron that the incrus-
tation arises. These facts are but too well known to engineers,
who are fully cognizant of the difficulty under which they labor
in endeavoring to remedy the evil.

The same evil obtains in regard to gas-pipe, only in a less
degree. The corrosion forms dust and scales, which drop off in
time, and obstruct valves, traps, elbows, and connections. This
is especially observable in inclined and vertical piping, such as
lamp-posts, etc.

It has been a question with practical men, whether to substi-
tute some other material for iron, or to adopt some means of
internally coating iron mains, so as to preclude all possibility of
the formation of accretions.

Methods have been tried to coat the interior of iron water-
pipes with some substance which would protect the surface of
the iron from contact with the water. This would seem to be the
only remedy, but attempts in this direction have heretofore been
attended with so much expense as to remove one of the strongest
arguments in favor of the employment of iron, namely, the econ-
omy of its application. Some few years ago, the AVater Board
in Brooklyn coated the interior of their iron main with a mixture
of coal tar and linseed oil, applied at a high temperature, but we
have never heard whether that remedy has been effectual in
checking the formation of accretions. It was said to impose an
additional cost of 2 dollars per ton on the mains.

Recently, Prof. Henry Wurtz, of New York, has invented a
peculiar cement for making gas or water pipes, and especially
adapted to coat the interior of gas mains, to make them perfectly
impervious even to hydrogen gas, and to prevent corrosion.

Among the materials, other than iron, which have been com-
mended and used to some extent for water pipes, "are wood;
iron-bound wood, and cement, and bituminized paper.

Plain wooden pipes have been inimemorially employed in some
places for distributing water, and are still used in many instances.
Pipes made of wood and cement have also been adopted to a liin-

60 ANNUAL OF SCIENTIFIC DISCOVERY.

ited extent. The} 7 are durable, easily made, and have been made
to withstand a pressure of 400 pounds to the square inch.

The pipes constructed of sheet iron, lined and coated exter-
nally with hydraulic cement, are said to be well adapted for dis-
tributing water where very cold weather does not prevail, frost
being inimical to the integrity of the pipe. So also is high pres-
sure said to be liable to injure the continuity of this kind of pip-
ing, especially at the numerous joints and connections.

In England, pipe made of bituminized paper has been employed
in distributing both water and gas, but we have not heard that
it has become popular to any great extent. It also was attempted
to be introduced into this country, but without success, we be-
lieve.

Another description of pipe is constructed of wood, being bored
from the solid log, lined with cement, and coated externally with
coal tar. This form of pipe is said to be extremely durable,
and, not being subjected to expansion and contraction by change
of temperature, is entirely free from leakage.

In England and France, as well as in this country, the com-
plaints on this score are wide and deep, and a wide lield is open
for enterprise in introducing an especial remedy.

TWIST DRILLS, AND RECENT IMPROVEMENTS IN THEIR MAN-
UFACTURE.

We condense from a paper recently read, by Mr. G. Lauder,
C.E., before the Liverpool Polytechnic Society, the following
remarks upon twist drills :

The last half century has witnessed many important improve-
ments in engineers' tools. Self-acting machines have been intro-
duced and improved, in numbers too great to mention in this
paper.

The leading idea which seems to have controlled in all these
improvements is what has been designated the "guide princi-
ple." As examples, we may cite the slide-rest, the planing-nm-
cliine, etc., the objects to be attained being, first, greater accuracy
in the work performed, and, second, greater speed. in performing
it.

After improved machines, which have enabled us to attain the
first object, we have to look to the forms of the tools used in these
machines, to^enable us to attain the second object, speed.

Tools for cutting metals are divided into two classes, namely,
paring tools and scraping tools, these being distinguished by the
edge they present to the metal being cut.

The data on which our knowledge of paring tools is founded
are altogether derived from practice in the workshop, workmen
themselves, he believed, having been, in a great many cases, the
leaders in improvement. The best cutting angle has been found,
for iron and steel, to be from 60 to 70, and Ithe angle of relief
3.

Drills have been the last tools in common use by working en-
gineers to come under the whip of improvement, a large propor-

MECHANICS AND USEFUL ARTS. 61

tion of those now in use being of the worst conceivable form to
effect the object they are designed for.

The speaker referred to the common form of drill, and, at the
same time, exhibited a sheet of drawings on which a number of
different forms of drills were marked. Some of them depend for
cutting action on, to use a homely phrase, "strength and stu-
pidness," no attempt whatever being made to form a proper
cutting angle. Others are more advanced in form, and have a
proper cutting angle provided ; sometimes a small portion of the
bottom end, he said, is turned, and forms, in this condition, a
very excellent working tool indeed. A twist drill was next
spoken of, which was the real object of bringing this paper under
the notice of the society.

These. drills have been known for a considerable length of
time, but have not been much used in this country until recent
years, Americans having been ahead in their use, and in manu-
facturing them as well. Strange as it may appear, it is still true,
that all the drills of this class were, until within a recent period,
imported from the United States.

Due consideration being given to the principles already ex-
plained, the advantages arising from the use of twist drills will
be apparent at a glance : first, they serve as a common drill, to
bore a hole ; second, they serve as a guide, while boring, to keep the
hole true ; and, third, they are so formed as to provide the proper
cutting angle throughout their whole working length ; fourth, they
are tempered throughout their entire working length ; fifth, they
are ground up true to standard sizes, thus obviating any neces-
sity for dressing. This last advantage will doubtless be highly
appreciated by all who have had practical experience of the con-
tinual trouble and loss incidental to the wearing out of size of
common drills.

The speaker then said, until the recent improvements which I
am about to lay before you were perfected, twist drills were
formed entirely by the clumsy method of cutting them out of a
solid round bar, by means of milling tools, then turning, temper-
ing, and straightening; it is but justice, however, to the parties
who have been hitherto engaged in the manufacture, to say that
their arrangements and machines for that purpose were admira-
ble of their kind.

The method now pursued successfully in this country differs
entirely from that just mentioned. First, the bar of steel which
is destined to form the drill is rolled into a special shape ; it is
then cut into lengths and again rolled in cam rolls, which form a
straight groove, after which the shank is formed by cresses.
Next the blank, as it is now called, is passed to the twisting-
machine, which consists essentially of a hollow spindle having a
perforated nut in the end to receive the blank. This spindle,
when the machine is started, has a motion of rotation on its own
axis, and also a motion of translation in the direction of its axis,
being thus adapted to twist the blank, then held firmly at the
outer end by vise clamps. Other clamps, worked by suitable
gearing, close on the blank as the central- spindles clear them ;
6

C2 ANNUAL OF SCIENTIFIC DISCOVERY.

these serve to hold the twist given to the blank. After a blank is
twisted the clamps open, the blank is withdrawn, and the twist-
ing-spindle returns to its starting-point.

After twisting, the drills are centred and rough ground, then,
hardened by heating in a lead bath and cooling in cold water,
next tempered in an oil bath, and finally finished by grinding to
a standard gauge.

The main features in this method, to which it was desired to
direct attention, are the forging and twisting, in contrast to
cutting from the solid bar. One of the principal difficulties, in
carrying out the new system just described, was getting the
blanks forged, accuracy being essential ; this difficulty overcome,
the benefits became manifest. Recent experiments have shown
that, in shaping metals, nothing is of greater importance than at-
tending to the " flow of the metal." Every particular shape into
which a bar of iron or steel is forged having an arrangement of
the particles which compose it peculiar to itself, any departure
from this natural arrangement is prejudicial. By forging and
twisting these drills, this law is paid the fullest attention to, each
drill being finished, so far as shape goes, before a single particle
of metal is cut from it.

By way of reward for attention to this natural law, the number
of drills lost from water-cracks, in hardening, is inappreciable as
affecting the cost of production. Scientific American.

THE ROYAL ALBERT HALL OF ARTS AND SCIENCES. A MAG-
NIFICENT SYSTEM OF HEATING AND VENTILATION.

The subject of heating and ventilation is one of ever recurring
interest, and of universal importance. We, therefore, copy
from "Engineering '' the following description of the apparatus
employed in the immense Royal Albert Hall, in London, one of
the largest public buildings in the world :

When it is considered that the Albert Hall of Arts and Sciences,
now in course of erection at South Kensington, is to accommodate
about 8,000 persons seated, the magnitude of the arrangements
for preserving an equable temperature and a pure atmosphere
will be realized. The capacity of the hall amounts to 5,000,000
cubic feet, so that the warming and ventilation caused the com-
mittee some anxiety, and they invited a limited number of engi-
neers to send in plans for effecting those objects. The various
plans submitted were carefully considered, and it was finally
resolved to adopt that of Mr. Wilson W. Phipson, Assoc. Inst. C.
E., which is now being carried out under his immediate superin-
tendence. The main points by which any arrangement had to be
governed were economy in warming, and a satisfactory combina-
tion of this process with that of ventilation. The heating-power
determined on by Mr. Phipson consists of an arrangement of dis-
tinct coils of hot-water pipes, placed in 3 air-chambers. One of
these chambers is carried under the main corridor, a second runs
beneath the seats of the amphitheatre stalls, whilst a third passes
under the arena. These 3 chambers are connected with 2 fans,

MECHANICS AND USEFUL ARTS. 63

the combined supply of air from which will be about 3,000,000
cubic feet per hour. One of these fans blows to the right and the
other to the left, the fresh air drawn from the outer atmosphere
being thus distributed through the chambers. This air, warmed
by the hot-water coils, is conveyed to the body of the hall from
the chamber under the main corridor by means of channels built
in the walls. These channels are also in communication with the
corridors, boxes, and all the adjoining private rooms. From the
chamber beneath the amphitheatre stalls the warm air finds its
way into the hall through perforations in the risers of the seats.
From the arena chamber the air enters the building through the
interstices between the floor-boards. By these arrangements the
entire power of the apparatus may be concentrated on the hall,
thus thoroughly warming every portion of it; at the same time
means are provided for warming the enclosed rooms independ-
ently when necessary. The amount of heating-surface in the iron
pipes required to carry out this arrangement is about 28,000
square feet. The temperature the apparatus fs calculated to
maintain in the hall is about 58 Fah. as a mean during the winter
months.

The fresh air is supplied to the fans through 2 air-shafts, 6 feet
by 6 feet, which are situated at the south-eastern end of the
building, near the Horticultural Gardens. In each of these shafts
is placed a self-acting valve, fitted with an index dial which
registers the amount of air passing into the building. Arrange-
ments are also provided in these shafts for cooling the air in its
passage to the hall in summer by means of sprays of water.
The fans are 5 feet 9 inches in diameter, and are to be worked by
2 direct-acting engines of 3 horse-power each. The heating
apparatus fixed in the air-chambers consists of 16 distinct coils of
4-inch hot-water pipes, heated by condensing boilers so arranged
that each condenser has its direct coil of pipes to work. By this
means either a part or the whole of the coils may be utilized,
according to the temperature of the external air. These condens-
ers are supplied with steam from 2 boilers belonging to the pump-
ing engines of the Horticultural Gardens. In case of need a sup-
plementary boiler will be provided, which will give a total force
of about 75 horse-power.

The modus operandi will be as follows : The temperature of
the hall will be raised to the requisite degree by the time the
audience arrives ; as soon as this point is reached, and whilst the
public are being admitted, the air-entrances to chambers Nos.
2 and 3 will be partially closed by means of valves. This
will allow of only one-sixth of the amount of air necessary for
ventilation to pass through these sources. The remaining five-
sixths will be distributed by means of 4 separate channels to the
air-chamber No. 1, under the corridor. From this chamber the
air will be distributed equally all through the entire building by
means of the air-channels formed in the walls, to which we have
already alluded. It will thus issue upon every floor into the body
of the hall, being admitted as far as possible from the audi-
ence.

64 ANNUAL OF SCIENTIFIC DISCOVERY.

The ventilation is provided for by an opening, having an area
of 120 square feet, for the escape of the vitiated air, which is
formed in the centre of the ceiling at the highest possible level.
This opening is surmounted by a shaft rising some feet above the
roof, and which is fitted with regulating louvres. The heat gen-
erated by the system of lighting the hall will increase the suction
of this shaft at night. During day performances, however, con-
tinuous circulation will be insured by a ring of gas-jets from burn-
ers with which the shaft is provided.

From a recent visit to the Albert Hall, we are enabled to re-
port the satisfactory progress of the building generally, under
the able superintendence of Colonel Scott, R.E. With regard to
Mr. Phipson's arrangements, we found that the pipes for heating
were all fixed in the outer circle main heating-chamber, and the
connections were being made with the steam-pipe to the condens-
ers. About one-third of the inner circle-chamber is completed,
and the remainder of the work is progressing. On Wednesday
week the wedges between the crown of the roof of the hall and
the scaffolding which had previously supported it were struck.
The results of this operation were highly satisfactory, the total
deflection being only five-sixteenths of an inch. The roof, be it
remembered, is of wrought iron, and covers an elliptical area of
220 feet by 185 feet, with a rise of 33 feet. Scientific Ameri-
can.

HEAT BY MEANS OF ILLUMINATING GAS.

" Gas, as a combustible," said M. Cazin, at a recent scientific
conference, " offers the best solution of the problem of distribution
of motive power in large towns where the illumination by gas is
already established. The pipes which furrow our cities convey
a provision for light, for heat, and for motive force. We de-
manded primarily of the gas the first of these agents ; we have
demanded also the second ; it is now time to demand of it all that
it is capable of affording. Why should not the same apparatus
afford to the workman in his shop light, heat, and power ? When
gas becomes cheaper this remarkable amelioration of the lot of
the artisan will be realizable." We will add that the obstacles to
the employment of gas as a source of motive power arise not
only from its high cost, but also from its disagreeable odor, and
the absence of proper means for good combustion. The odor
which is produced chiefly at the commencement of the operation
is produced by condensation of some of the products of the com-
bustion upon a cold surface. It may be prevented in a great
measure by previously heating the generator with another com-
bustible. With regard to an efficacious burner, we do not know
of any ; Bunsen burners, which are generally preferred, afford
hardly one-half the calorific power contained in the gas. The
Parisian Company have directed a series of trials upon the calo-
rific capacity of illuminating gas, which give sensibly the same
results. Copper tubular boilers were employed of a capacity of
10 to 30 litres. The heat was obtained from 2 Bunsen burners

MECHANICS AND USEFUL ARTS.

65

with flames from 20 to 25 centimetres high. The bottom of the
boiler was placed so as to receive the flame at the height of 14 to
16 centimetres above the base.
The following table exhibits the results of the experiment :

Temperature of the
Water.

Time of Heating.

Expenditure of Gas.

Gas used for each lOc.
of Heat.

Degrees.
10

Minutes.

*

Litres.

Litres.

35

10

ICO

64

60

15

188

78

80

15

191

95

90

7

100

100

100

7

100

100

54

739

The boiler weighed 6.5 kilogs. ; it contained 29.5 kilogs. of
water. The number of calorific units produced was therefore 6.5
X 9*-f29.5 X 90f ==2,713.5. This corresponds to 3,700 units
to the cubic metre of the gas. Van Nost. Mag.

A NEW ROTARY PUMP.

This machine works very simply, and, after the manner of cer-
tain canals in the animal economy, imitating the vermicular or
peristaltic movements of the intestines in their spontaneous mo-
tions which aid digestion. Revolving arms, turned by a crank,
carry friction rollers, which, in rolling upon an elastic tube, press
before them the liquid or gas that it contains, while the tube,
regaining its form after the. compression, exerts an aspiration
proportioned to the elasticity of its sides. The plan is admirably
adapted to all the requirements of stowing or transporting wines.
For the use it offers the following advantages :

1. The wine traverses the pump without shock (batter), an
important consideration, and belonging especially to this machine.
While in ordinary pumps the wine sustains considerable beating
and jolting, in this new apparatus it passes over as in a siphon,
and flows," without encountering any obstacle, in an open canal.

2. The wine undergoes no alteration by its passage through the
tube ; long experience having proved that the rubber of which
the tube is made cannot injure the most delicate wine.

3. There is no contact of the liquid with any oxidizable metal-
lic surface, nor with greasy crated surfaces, such as, unfortu-
nately, occur in all other present s} 7 stems.

4. This pump yields a greater useful effect, in proportion to the

* Calorific capacity of the copper.
6*

f Ileat obtained from the gas.

C6 ANNUAL OF SCIENTIFIC DISCOVERY.

y

force applied, than any other pump, whether reciprocating or
rotary.

5. When it is desirable to empty the conducting tube, as when a
cask has been filled, it is only necessary to reverse the motion of
the pump, and the excess of wine is returned to the reservoir.
This manoeuvre, so simple and so advantageous, is impossible
with any other system.

6. The tube is easily and promptly filled.

7. It serves to agitate the wine at the moment of sizing, by
forcing through the siphon a powerful current of air.

8. Finally, this new wine-pump requires no care to keep it in
order ; it can be cleared with facility, or repaired, if necessary,
without having recourse to a special workman ; the replacing of
the rubber tube, after very long use, being all that is necessary.

This pump was invented by MM. Mackintosh & Guibal, the
celebrated rubber manufacturers. It has been extensively used
by wine and beer manufacturers, who testify to its advantages.
By using porcelain rings for ends and joinings, it may be used in
pumping vinegar. If prepared rubber be substituted for the
natural product, the pump will be very serviceable in raising pe-
troleum and similar oils. Van Nost. Eng. Mag.

A CONCRETE FROM GAS-LIME.

It is well known that gas companies turn out of their works a
quantity of lime which has absorbed certain impurities from the
crude gas. Hitherto, the only use found for this offensive smell-
ing gas-lime has been the very limited one of spreading it on the
land and at the roots of trees for killing insects hurtful to vegeta-
tion. Of course this is out of the question in the case of the large
city gas-works, whose plant is too far removed from fields and
orchards, and, although it is acknowledged that gas can be better
purified by lime than by any other material, the trouble of re-
moval of the waste product has forced the adoption of other meth-
ods which do not involve so much expense in carriage.

According to the London "Builder," Mr. Thomas Prideaux, of
Sheffield, has been exhibiting blocks of concrete, mouldings, arti-
ficial stone-slabs for hearthstones, and other objects, all made
from this refuse gas-lime ; and as it is now the subject of a patent,
and promises to furnish a useful material for building purposes, a
short account of the results obtained up to this time may be use-
ful. The gas-lime is ground under edge-stones, and presents at
first a uniform green color. In this state it forms the raw mate-
rial for making plaster or cement of various qualities and capabil-
ities. According to the purpose required, it is used in this state,
or it is calcined and reground and mixed with silicons matters.
A wall may be covered with a smooth coat, which hardens free
from cracks, for interiors ; basements may be covered with a dry
coat of cement, impervious, it is asserted, to damp, and quite
obnoxious, be it remarked, to cockroaches. A hearthstone may
be formed, and sets in a few days into a hard block of stone, as

MECHANICS AND USEFUL ARTS. 67

well as mantel-pieces and jambs, which, without any coloring-
matter, present a neat and stone-like appearance.

It is remarkable that the peculiar odor of the gas-lime is no
longer to be detected when the cement has set. The sulphur
compounds are oxidized rapidly, and some of the adhesive quali-
ties of the cement are no doubt due to the formation of calcium
sulphate or plaster of Paris throughout the mass of the material
in the process of hardening. A rubble-wall can be built up and
plastered over to resist the action of water in the interval of a
tide, as the properly prepared cement will set even under water.
The latter property has induced Mr. Prideaux to propose its use
for building sea-walls.

A number of houses in Sheffield, where trial has been made of
this material, have been visited and inspected since its first
application to walls, floors, and hearthstones, now about 12
months ago, and time only appears to tell in favor of its dura-
bility.

PRESERVATION OF CAST-IRON WATER-PIPES.

In 1858 the cast-iron pipes carrying the Cochituate Water from
Boston to South Boston were treated with a preparation from coal
tar, known as Dr. Smith's process, and the result has been so
favorable that it has been permanently adopted by the Cochituate
Water Board, and by the managers of other water works through-
out the country, where the materials used for pipe is cast iron.
The pipes laid in 1858 were taken up and examined after 10
years 1 use, and were found nearly free from rust or ochrous accre-
tions. This coal-pitch varnish is applied substantially accord-
ing to Dr. Smith's process, which is described as follows in the
specifications :

Every pipe and casting must be entirely free from dust, sand,
or rust, when the varnish is applied.

The varnish or pitch is to be made from coal tar, distilled until
all the naphtha is removed, the material deodorized, and the
pitch reduced to about the consistency of wax or very thick mo-
lasses ; pitch which becomes hard and brittle when cold will not
answer for this use.

Pitch of the proper quality having been obtained, it must be
heated in a suitable vessel, to a temperature of 300 Fahrenheit,
and must be maintained at not less than that temperature during
the dipping. As the material will deteriorate after a number
of pipes have been dipped, fresh pitch must be frequently added,
and at least 8 per cent, of heavy linseed oil must be added daily
with the fresh pitch, and the vessel must be entirely emptied of
the pitch and refilled with fresh material as often as may be nec-
essary to insure the perfection of the process.

Each casting shall be kept immersed from 30 to 45 minutes,
or until it attains the temperature of 300 Fahrenheit, and, if
required by the engineer, shall be heated to such temperature as
he may designate before it is dipped.

After the bath is completed, the castings will be removed and

68 ANNUAL OF SCIENTIFIC DISCOVERY.

placed in such a position to drip that the thickness of the varnish
shall be uniform.

The coating on the pipes and castings must be tenacious when
cold, and not brittle, nor disposed to scale off; and when it shall
appear to the inspector that the coating has not been satisfactorily
applied, the pipe or casting shall be thoroughly scraped, cleaned,
and recoated.

COATING FOR OUTSIDE WALLS.

The following coating for rough brick walls is used by the
U. S. Government for painting light-houses, and it effectually
prevents moisture from striking through : Take of fresh Rosendale
cvnient 3 parts, and of clean, fine sand 1 part; mix with fresh
water thoroughly. This gives a gray or granite color, dark or
light, according to the color of the cement. If brick color is de-
sired, add enough Venetian red to the mixture to produce the
color. If a very light color is desired, lime may be used with the
cement and sand. Care must be taken to have all the ingredients
well mixed together. In applying the wash, the wall must be wet
with clean fresh water ; then follow immediately with the cement
wash. This prevents the bricks from absorbing the water from
the wash too rapidly, and gives time for the cement to set. The
wash must be well stirred during the application. The mixture
is to be made as thick as can be applied conveniently with a
whitewash-brush. It is admirably suited for brick-work, fences,
etc., but it cannot be used to advantage over paint or whitewash.

PRESERVATION OF STONES.

Dr. Robert, in the Paris " Les Mondes," maintains that the use
of the black oxide of copper, and its salts, will effectually prevent
change in stone. He shows that the decay of granite, marble,
limestones, sandstones, and all natural building stones, is the
combined effect of various causes, and that among these is a very
minute lichen, the Lepra antiquitatis, which is one of the worst
enemies of stone, and its action is to such an extent that, for in-
stance, the beautiful marble sculptures of the well-known Pare
de Versailles will, unless proper measures be taken for staying
the process of decay, be unsightly and ugly masses of dirt, and
quite irretrievably lost, as works of art, within the next 50 years.
The author, taking as instances such buildings at Paris as the
Bourbon Palace, the Palais du Corps Legislatif, the Mazarin Pal-
ace (V Institut} , the Mint, and others, points out that dust, spiders'
webs, and the action of rain, combined with the minute lichen
above alluded to, hasten the decay of stone, especially of those
parts where any sculpture or ornamental carving promotes the
deposition of dirt and dust. Various places and instances are
cited of the application of oxide of copper and its salts, which
places are open to inspection, and the length of time which has
elapsed since such application seems to warrant the conclusion
that these compounds act as preservatives of stone. In reference

MECHANICS AND USEFUL ARTS. 69

to granite, the author states that this stone is also, according to
the experience of Egyptian engineers, far more readily affected
by a moist climate than one would be led to believe. The obe-
lisk of Luxor, brought from Upper Egypt to Paris, has become
blanched and fall of small cracks, during the 40 years it has stood
on the Place de la Concorde ; although 40 centuries had not per-
ceptibly affected it as long as it was in Egypt. Granite in a
moist climate becomes the seat of a minute cryptogamic plant,
which greatly aids its destruction ; and it is, moreover, a well-
known fact, that the disintegration of this stone, which is com-
posed of 3 separate minerals (quartz, mica, and feldspar), de-
pends very greatly upon the thorough and intimate mixture, as
well as the chemical composition, of these 3 ingredients, each of
which, in a separate state, more easily withstands the influence
of the weather.

PRESERVATION OP STONE.

The preservation of brown sandstone, which has become so
popular as a building material, has also been the subject of exper-
iment ; and concrete building, as well as the manufacture of arti-
ficial stone, has been slowly but surely advancing.

Our readers will recollect some editorial remarks upon the sub-
ject of " Improved Building Materials," published not long since
in this journal. The subject will bear further attention in connec-
tion with recent improvements.

There seems to be a general effort now making to produce
cheaper and if possible better building materials than have hither-
to been employed. Our exchanges from abroad, more especially
those devoted to architectural topics, give us very encouraging ac-
counts of the progress of concrete building. This style of build-
ing seems growing in favor, and is furnishing a very goodclassof
dwellings at a very cheap rate.

We find also an account of a new kind of artificial stone, called
the Victoria stone, which seems to have endured severe tests and
to promise well.

It is the invention of a clergyman, Rev. H. Highton. The pro-
cess by which it is made consists in mixing broken granite with
hydraulic cement, and steeping the whole, when set, in a solution
of silica. The granite used is the refuse of the quarries, and is
broken up at the works. It is then mixed with Portland cement,
in proportions of 4 of granite to 1 of cement, sufficient water being
added to give it a pasty consistency. In this state it is placed in
moulds, when it consolidates in about 4 days. When taken from
the moulds it is placed for 2 days in a solution of silicate of soda,
which completes the process.

The silicate solution is prepared in a peculiar manner, and upon
it the success of the operation depends. The silicate of soda has
the property of hardening any kind of concrete in which lime is a
component. This substance has been hitherto too costly for gen-
eral use in artificial stone manufacture, and it becomes caustic by

70 ANNUAL OF SCIENTIFIC DISCOVERY.

the absorption of its silica, so that it attacks the hands of the work-
men.

Mr. Highton produces his solution in the following manner. He
uses a soft kind of stone, containing 25 per cent, of silica, found at
Farnham, in Surrey, England. This stone readily dissolves in a
cold caustic soda solution.

The solution of soda is placed in the tanks used for steeping the
stone, and the Farnham stone is ground and added to the bath.
The lime in the artificial blocks removes the silica from the solu-
tion, which in its turn takes up more silica from the Farnham stone,
and so maintains its supply of silica, thus removing the objections
above named. The process is extremely ingenious, and we are
informed that flagging, sinks, mantels, coping, cap-stones, sills,
etc., are produced by it. Finely cut mouldings are not success-
fully produced, and it seems better adapted to a heavier class of
work.

In America also considerable improvement is observable in this
field. A Brooklyn paper states that porcelain enamelled bricks are
now produced by a firm in that city, of great beauty, both for out-
side and inside work, and at a cost not exceeding that of Phila-
delphia pressed bricks. Scientific American.

ARTIFICIAL STONE. THE SOREL PROCESS.

There is no field of invention which to-day is more replete with
general scientific and practical interest than that pertaining to
the manufacture of artificial stone. While, in the working of
iron, men have sought out means whereby it can be rapidly and
cheaply converted into the forms required, the world has, to the
present day, been content with working stone after the same gen-
eral method used in the construction of the pyramids. The rud-
est of all materials is thus changed by immense labor into costly
forms ; and the attempts to obviate the necessity for this labor
and expense have been confined to a very recent period.

The idea that stone could be cheaply produced by artificial
means, and moulded to any form required, has gradually forced
itself upon the minds of modern inventors, and has borne fruit
in a large number of processes more or less practical and adapted
to secure the end in view.

Very many of these processes have, however, failed to secure
such results as to warrant their general adoption. Some require
the steeping of the stones in some solution after they are moulded
to remove or transform some contained material, or to add some-
thing which could not be advantageously added in earlier stages

fj d7 v ^5

of the process. Among these is the celebrated Ransome process,
which has not given uniformly satisfactory results.

Other sorts of artificial stones are sand concretes, made with
cements of various degrees of hydraulicity, and many of them
of such inferior quality as to render them utterly unreliable for
use as building material.

CJ

The process invented by M. Sorel, a celebrated French chemist,
produces results which we have never seen equalled by any other.

MECHANICS AND USEFUL ARTS. 71

It has for its basis the use of oxychloride of magnesium, a new
cement discovered by M. Sorel, who was also the discoverer of
oxychloride of zinc. The process has been patented in this
countiy, and the patent is owned by the Union Stone Co., of Bos-
ton, Mass., who apply it to the manufacture of all kinds of stone
moulded in ornamental forms for building purposes. They also
apply it to the manufacture of emery-wheels, needle-sharpeners,
oil and water stones, soapstone register rings, and faces for sad-
irons, etc. In short, they work any kind of stone by this process,
first disintegrating it by suitable mills and moulding it again into
any form wished, and by the use of the cement named consolidat-
ing the mass to even greater strength than it originally pos-
sessed, without alteration of color or apparent texture.

We have now before us specimens of marble, sandstone, blue-
stone, etc., which look exactly like the original stone, yet which
are even more dense and hard than the stone from which they are
made. The marble, which is a beautiful specimen, having a fine
crystalline fracture, was made of common marble-yard refuse.
In fact, there is no sort of mineral solid material which the mag-
nesium cement does not seem capable of uniting, and holding
with great tenacity. The process of making stones by this method
is as follows: Natural magnesite carbonate of magnesia is
first calcined, which reduces it to the oxide of magnesium. In
this state it is mixed diy in the proper proportion, by weight, With
the powdered marble, quartz, sand, or whatever material forms
the basis of the stone. It is then wetted with bittern water,
which converts the oxide of magnesium into the oxychloride.
The now semi-plastic mixture is rammed into moulds, where it
speedily hardens sufficiently to be taken out and laid on skids.
In 2 hours' time the stone is so hard that the heaviest rain will
not wash the corners off, and in from a w r eek to two weeks the
stones may be marketed and used.

These stones are, according to good authority, capable of with-
standing even more severe weather tests than natural stones.
Tests made in Boston as to their strength are certified to have
given better results than natural stone ; and certainly the speci-
mens w r e have, indicate that they are in no way inferior to the
natural stones they severally represent.

The hydraulicity of magnesium salts has attracted the attention
of several of the most eminent chemists in the world.

In a note recently read before the Academy of Sciences, in
Paris, by M. Deville, he called attention to the action of water
upon magnesia. A portion of a specimen of magnesia, prepared
by calcining the chloride sent him several years previously by
M. Denny, was kept constantly exposed to water under the taps
of his laboratory. After a time it assumed a remarkable con-
sistence, it could scratch marble, and, though subjected to atmos-
pheric action for 6 years, it underwent no perceptible change.

The substance proved to be a crystallized hydrate. Subse-
quently, with magnesia prepared from the hydrate, he obtained
similar results, and casts of medals after having been placed in
water assumed the appearance of marble.

72 ANNUAL OF SCIENTIFIC DISCOVERY.

Magnesia, obtained by calcination of the chloride prepared by
treatment of sea-water, though its hydraulicity is partially de-
stroyed by calcining at a white heat, exhibits remarkable hy-
draulic qualities when brought to a red heat. Equal parts of
chalk or marble and magnesia formed into a plastic mass, be-
come hydrated and extremely hard when acted upon by water.
A paste made from dolomite, calcined below a red heat and pow-
dered, forms, under water, a stone of extraordinary hardness.

The experiments of M. Deville show that to the hydraulicity of
magnesia is due the union of the particles of chalk or marble in
forming a compact, homogeneous stone, and numerous obvious
applications of this property of magnesia in the arts will readily
suggest themselves.

M. Fremy, in his published researches on hydraulic cements,
attributes the setting of hydraulic lime, first, to the hydration of
the aluminate of lime, and, second, to the reaction of the hydrate
of lime upon the silicate of lime, and the silicates of alumina and
lime.

It is evident from these observations that the oxychloridc of
magnesium is a cement of great power and durability, and that
as an hydraulic cement it ranks among the best known to modern
science. Its application to artificial stone manufacture, we think,
solves the problem of how to make such stones of proper density,
durability, strength, and capability of taking a high polish. If
we may credit the statements in regard to cost of manufacture,
there seems no reason why stones of this kind should not be able
to more than compete with cut stones of any variety and for any
purpose. Scientific American.

THE DARIEN CANAL SURVEY.

The United States government expedition sent to survey the
Darien Isthmus has returned. Owing to unavoidable causes the
expedition did not reach the Isthmus till about April 1. They
immediately landed at Caledonia Bay and made a careful explo-
ration of the route proposed by Dr. Cullen. They found the
lowest mountain pass to be over 600 feet above the sea level. About
the first of May the party proceeded to explore the San Bias route
from Mandinga Bay, on the Atlantic, to Chepo, at the southern
end of Panama Bay, on the Pacific. This route, Com. Selfridge
thinks, is available. Tire rainy season commenced before he
landed at San Bias, and all the country was flooded with water,
yet from his reconnoissance he thinks that a careful survey will
develop a route whereby a canal can be made with only 27 miles
of cutting. We are pleased to see that he is already ordered to
reorganize his expedition for a renewal of the survey next winter.
The route favored by Com. Selfridge is the narrowest point of the
Avhole Isthmus. It is said that the tidal waters of the two oceans
there come regularly within 7 miles of each other, and it is there
that the tradition exists that the Indians and buccaneers drew their
canoes across. It was there, too, that Vasco Nunez di Balboa
lauded, and journeying toward the Pacific first saw the waters of

MECHANICS AND USEFUL ARTS. 73

that ocean from the heights south-east of Panama. The harbors
on both sides are good. This route was brought before the pub-
lic by Mr. Oliphant in a lecture before the British Geographical
Society. It was reconnoitred for F. M. Kelly, Esq., of New
York, in 1864, and, while having many favorable points, was re-
ported against on account of a proposed tunnel, the engineers
at the same time stating that they believed a better route could
be found.

One of the great objections urged to this part of the Isthmus
has been supposed unhealthiness. Com. Selfridge reports that his
men had good health, and only one died. This from a crew num-
bering fully 600 men does not indicate a very unhealthy climate.

As Com. Selfridge is to proceed again to the Isthmus next win-
ter, and we suppose not only make a thorough survey of the San
Bias, but also of the Panama route, some definite information may
at last be expected as to an American interoceanic canal. Then,
too, we notice that Congress is about to appropriate 35,000 dollars
for the survey of the Tehuantepec line.

SUEZ CANAL.

The report of M. de Lesseps, presented to the shareholders at
Paris, states that 1,600,000 dollars will be required this year to com-
plete or improve the works. The total number of vessels passed
through the canal, from the day of its opening to the 15th of March,
was 209.

In the report of Captain Richards, R.N., and Lieut. Col. Clark,
C.B., sent by the English government to examine the canal, with
reference to the future utility of the same to the English marine,
we observe that by 52 accurate sections, taken at different points,
the canal is found to be essentially completed according to the
original, or rather modified, designs of the company, and '* is, at
the present moment, undeniably a navigable canal for vessels of
considerable draft and tonnage."

It appears that the company intend, without delay, to reduce
the sharpness of certain curves, and widen the bed at these points
to 130 feet on the floor ; also to make the channel at Port Said
30 feet deep. This will require the removal of about 451,000
cubic yards of earth.

It is also intended to mark the banks of the canal by conspic-
uous beacons at each mile, and to provide posts or bollards for
securing ships or heaving them off at every tenth of a mile, and
to mark the limits of 16 feet water on each side by buoys placed
about 400 yards apart.

According to the same report, no difficulty is to be apprehended
in regard to the harbor of Port Said, either with reference to
keeping the channel open or in its approach by vessels.

So, also, as to the silting up of the canal by drifting sand, the
permanence of the fresh-water canal, now 10 years old, is con-
clusive evidence upon this point.

The authors of this report further conclude that the use of this

74 ANNUAL OF SCIENTIFIC DISCOVERY.

canal will be decidedly advantageous to several classes of war
vessels and to the mercantile marine. Journal Franklin Institute.

SURVEY OF THE ISTHMUS OF DARIEN FOR AN INTEROCEANIC

CANAL.

The expedition for the survey of the Isthmus of Darien to ascer-
tain the practicability of a route for the interoceanic canal, under
the command of Commander T. O. Selfridge, U.S.N., sailed
from New York in the latter part of January, 1870.

During 6 months of the year, a heavy sea breaks all along the
Atlantic border of the Isthmus, and, consequently, the necessity
of a good harbor narrows very much the field of research, which
a knowledge of the orology of the Isthmus also limits to a corre-
sponding degree. There are but 3 harbors on the Atlantic coast of
the Isthmus, adapted for the terminus of a canal, the Gulf of
San Bias, Caledonia Bay, and the Gulf of Uroba or Darien. The
first 2 are magnificent bays, easy of access, and entirely protected
from the north winds and heavy swell. The Cordilleras Lloranes
skirt the coast at distances varying from 3 to 8 miles, without a
break, except at the northern and southern extremities, while the
Chiman range, crossing the Isthmus, indicates that in the central
portion will be found the greatest amount of mountain area.

The survey was begun at Caledonia Bay in the latter part of
February. The whole face of the country is covered with a prime-
val forest, impenetrable from the thick undergrowth but by slow
and laborious cutting, through which the surveyor struggles with
his compass and level, seeing neither the sky above nor the country
around. In these circumstances it was soon evident to the com-
mander of the expedition, that the most practical as well as the
most expeditious method would be to carry on the survey up the
different water-courses. This would give at all times the lowest
level, the rivers would lead to passes in the mountains did such
exist, and the best results would be obtained in the shortest space
of time. As the work proceeded, should any route indicate a level
adapted for the proposed line, a more exhaustive survey would be
undertaken.

Reconnoissances with the barometer were made up all the streams
emptying into Caledonia Bay, including the Aglamate, Aglaseni-
qua, and Washington Rivers. While these were in progress, a
reconnoissance in force was made over the mountains to the Pacif-
ic slope down the Sucubti, until the villages of the mountain In-
dians, the Sucubti tribe, were reached. Here a treaty was made by
the commander with them, similar to one with the coast Indians,
and the exertions made to show them that we had not come to oc-
cupy the country, but merely to look at it, coupled with rigid orders
not to molest their property, enabled us at all times to remain on
the most friendly terms.

The result of these explorations failed to exhibit any signs of a
pass, and the line up the Aglaseniqua River, thence over the moun-
tains, giving the lowest average level, was selected as the one to
be surveyed.

MECHANICS AND USEFUL ARTS. 75

A line of levels was successfully carried from the sea over the
dividing range, at an altitude of 1200 feet, and down to the Su-
cubti, at a point about 3 miles below its sources, where an alti-
tude of 560 feet was obtained. A series of careful observations
were made with both the aneroid and mercurial barometers, at
the different bench-marks, whose height was already determined
by the spirit-level. They resulted in showing that the aneroid
barometer was totally unreliable, being often 100 feet in error,
while the extreme deviation of the mercurial barometer was never
more than 30 feet, and the average not more than 12 feet from
the correct height. The height of the Sucubti, by spirit-level 560
feet, was evidence sufficient that no pass below that altitude ex-
isted in the divide. This river with its tributaries, the Napsati
and Asnati, drain a large area of country, of which its bed must
necessarily represent the lowest level. ' Careful observations with
the mercurial barometer were made down the Sucubti to its junc-
tion with the Chucunagua, at which was found an altitude of 159
feet. 10 miles down the Chucuuagua an altitude of 99 feet was
obtained.

In all observations with the barometer a standard was also
noted at the sea-shore.

All idea of a pass in the divide being exploded, there remained
the sole test of a tunnel to decide upon the impracticability of
this route. Allowing the largest error ever obtained in our exper-
iments in the barometrical heights of the Sucubti, taking 30 feet
as the depth of our canal, and conceding that at 200 feet tunnel-
ling is more economical than open cutting, there will be found a
distance of 10 miles from an altitude of 200 feet on the Atlantic
slope to a corresponding one on the Pacific, or, in other words, a
tunnel of this length would be necessary. The country in the
vicinity of the Sassordi River presenting favorable indications from
the sea, a similar exploration and survey was carried on from.
Sassordi harbor, some 10 miles north of the previous surveys.
This was continued up the Sassordi River across the divide to the
Morti, but a like result was obtained, requiring a tunnel of 8
miles in length to span the mountain area.

The northern portion of the Isthmus, from the Gulf of San Bias
to the Pacific, forms the narrowest portion of the continent, but
30 miles in width. The shortness of this line, the appearance of
the interior from the sea, and the magnificent harbor, pointed it
out as the proper field for still further explorations. Work was
accordingly begun about the 1st of May, and though the rainy
season had begun, the favorable indications of this line filled all
with enthusiasm to push ahead in spite of the hardships and ob-
stacles arising from an inclement season. The line of levels was
carried up the Mandinga, the largest river emptying into the
Atlantic between the Chagres and the Atrato, and crossed the
divide at an altitude of 1100 feet.

It was continued in a S.S.E. direction down the Pacific slope,
till, at a distance run by level of 23 miles from the sea, it met, at
the junction of the Mnrmoniand San Jose Rivers, with the survey
of Mr. Keiley's in 1864, whose engineers ran a line of levels from

76 ANNUAL OF SCIENTIFIC DISCOVERY.

the Pacific up the Marmoni to this point. This survey in connec-
tion with Mr. Kelley's gives a line of spirit-levels from ocean to
ocean that, following the bed of streams which flow transversely
across the isthmus, present the lowest possible profile. The result
showed a mountain area of 10 miles that would require to be
tunnelled, an undertaking too costly to be profitable, if within
the limits of engineering, while the other portions of this route
present the most favorable aspects.

The southern portion of the Isthmus still remains to be ex-
plored. The government propose to continue these surveys the
coming season, which will be carried up the valley of the Tuyra,
across the divide to the Cacarica Lake, not far from the mouths
of the Atrato. This region was visited by Hellert, an experienced
German traveller, in 1845, who reported the divide not over 200
feet, but this is very unreliable, as he was so unfortunate as to
lose his instruments before it was reached. The expedition re-
turned to New York in July, and though not successful in finding
a proper route, have reaped a full reward for their labors in the
clearing away of all doubt from 3 separate routes, and their elim-
ination in the future from the field of research.

CENTRAL SHAFT HOOSAC TUNNEL.

At last, after years of toil, and at a cost of close upon half a
million of dollars, the great central shaft of the Hoosac has
reached the grade of the tunnel ; 1,030 feet below the natural sur-
face. This shaft is elliptical, the transverse diameter being 27 feet
and the conjugate 15 feet, passing the entire depth through a
compact mica-slate formation intermixed at intervals with white
quartz. At the commencement of the present contract with the
Messrs. Shanly, there required to be done 447 feet. This has
been accomplished since June 1, 1869, say in 15 months; giving
a monthly average of 29.8 feet. The largest month's work was
38 feet. At intervals of about 18 feet are floors of heavy timbers,
supported by " hitches " cut in the rock, connected by ladders, in
case of accident to the hoisting apparatus, and forming supports
for the wooden " guides," in which the cross-head travels, under
which is suspended the boiler-plate iron bucket, of a capacity of
about 400 gallons. The work has been impeded slightly by
water, of which the shaft makes nearly 3 inches per hour. To
raise this water, an engine of 60 horse-power is constantly work-
ing, pumping all the water which collects as far down as 650 feet,
caught in tanks by sloping " drip roofs." Below this, the water
on the bottom has been hoisted in the iron bucket, a bucketful
being sent up by the miners whenever the quantity became incon-
venient. Now, the shaft being at grade, a " sump " will be sunk
and a water-bucket with bottom valve used, thus avoiding the
tedious task of bailing into the bucket by hand.

Workmen are now employed trimming the sides of the shaft,
and preparing the " guides " for a wooden cage to be substituted
for the bucket so soon as the "headings," east and west, at the

MECHANICS AND USEFUL ARTS. 77

bottom, are sufficiently advanced to use rock cars, when the rock
will be raised to the top direct from the headings, cars and all.

The shaft being at grade necessitates, probably, the most deli-
cate and responsible professional act an engineer may ever ex-
pect to meet, it being necessary to lay down a line less than 27
feet in length at the bottom of a dripping dark shaft 1,030 feet
deep, so that both ends of the line being produced shall coincide
with the terminal points of the tunnel, each being distant over
12,000 feet from the centre of the shaft. To increase the initial
difficulty, the top of the shaft is on the summit of a rugged moun-
tain, from 1,500 to 1,800 feet above the grade of the tunnel at its
termini. It is no light responsibility to assume charge of this op-
eration. The State of Massachusetts has had manufactured a
colossal transit instrument, of the most elaborate and perfect con-
struction, costing 3,000 dollars. The most accurately verified
lines have been laid down over the mountain, extending long dis-
tances beyond in both directions to the tops of neighboring moun-
tains. By the accuracy of this instrument and its manipulation,
the line of 27 feet (the transverse diameter of the shaft) will be
permanently defined, requiring wonderful exactness, and from its
extremities the "plummet" alone can reach the bottom of the
shaft. These plummets must of necessity be weighty and beauti-
fully poised, and will require to be suspended in oil to produce
perfect rest and protection from the faintest vibration of the air.
The most delicate cords, consistent with strength, must be used
to suspend them, and after all is done that science can suggest
(being perfect as to theory) any intelligent mind can understand
how delicate and fraught with danger is the practical part of the
operation to the engineer, and what grave effects the slightest
error would produce on so small a base as 27 feet. It is quite
possible the motion of the earth may affect the plummets more or
less ; but this point has not yet been thoroughly investigated.

THE HOOSAC TUNNEL.

The Hoosac Tunnel, it is reported, is now progressing at the
rate of 10 feet a day, 4 feet from the west end, and 6 feet from
the east end. The central shaft is complete ; its depth to the floor
of the tunnel is 1,030 feet. Work at the new headings is already
begun. The tunnel has been excavated 11,765 feet at both por-
tals, that is, 6,946 feet at east side, and 4,819 feet on the west
side. Van Nost. Eng. Mag.

INTERNATIONAL COMMUNICATION.

Mr. Bessemer supplies the following description of his inven-
tion for improving stearn communication by the construction of
a suspended chamber. He says : " The experimental vessel is of
only 153 tons' measurement, and, although much too small to at-
tain the bust results, is, nevertheless, quite large enough to make
the Channel passage, and prove, beyond question, the practica-
bility, or otherwise, of the mechanical principle involved. Not

'/*

78 ANNUAL OF SCIENTIFIC DISCOVERY.

the least of the advantages which the new system of ocean tran-
sit offers is the shortness of the time and the small amount of
capital required to put it into operation at every seaport in the
kingdom. For instance, 2 steamers, fitted with means for the
most luxurious accommodation of passengers, in vessels of great
size, and having sufficient engine power to cross the Channel in
60 to 65 minutes, and fully adequate to carry the entire pas-
senger traffic, could be put on the station within 8 or 9 months
from the date of order, at a cost not exceeding 130,000. The
commercial advantages of such a system, as compared with those
proposals which would require some 8,000,000 or 10,000,000
sterling, and several years to execute, will be readily appre-
ciated by the public, the more so as my system will be subjected
to the test of actual trial before a shilling need be expended by
the public upon it. The proposed new system does not contem-
plate the employment of ships that shall be motionless except in
the direction of their course ; for the waves would strike on such
a vessel as on a rock, and dash themselves over her as they some-
times leap the Eddystone. It does not attempt to arrive at the
end desired simply by construction of ships or rafts of vast size,
for it is well known that the largest ships that have ever been
built roll frightfully in the Channel in bad weather ; nor is it by
any new and untried external form of the vessel, involving new
problems in navigation ; on the contrary, my system in no way
whatever interferes with the external form or with the sailing
qualities and safety of the vessel, the whole difference being in
the internal arrangements of the ship, and is based on the well-
known law that all bodies which revolve or roll, in so doing,
move about a centre where there is no motion, and all beams that
vibrate move also about a centre, from which point the distance
moved through by any part of the beam is as the distance from
this central point. Now, therefore, if we make the centres,
about which the vessel pitches and rolls, coincident with the axes
on which the saloon is suspended by suitable mechanism, and
provided with a heavy counterbalance weight beneath the centre
of gravity, the tendency of this weight will be at all times to
keep the saloon poised on the centre of the vessel's motion, and
therefore free from pitching or rolling, its floor remaining always
quiet and horizontal, while the vessel itself may be pitching and
rolling about the centre of suspension. The most convenient
form for such a saloon is circular, surmounted by a large dome,
lighted at the top with glass. It is proposed to make this circular
saloon of 50 feet in diameter, and 28 feet in height internally,
having a gallery extending entirely around its interior at about
9 feet from the floor. A continuous couch around this gallery
would accommodate 60 persons, while about 70 others would find
a similar accommodation below, independently of the large space
afforded by the floor of the saloon. This large and lofty apart-
ment, although much smaller, would present somewhat the gen-
eral appearance of the new reading-room at the British Museum.
It would be supplied with plenty of cool, fresh air from below,
which would pass off through the glass louvres in the dome.

MECHANICS AND USEFUL ARTS. 79

The saloon would be entirely separated from the rest of the ves-
sel by water-tight bulkheads, thus cutting off all unpleasant
smells from the engines and boilers. The suspension is so ar-
ranged that the vibration of the engines and propeller cannot be
transmitted to the saloon, which is also relieved from the con-
stant thud of the waves striking against the sides of the vessel,
because there is no contact between the ship's sides and the walls
of the saloon. Suitable ante-rooms leading from the saloon are
also provided for invalids, etc. The general plan also embraces
the construction of raised deck platforms, so arranged that those
who prefer the open air may have beneath them a steady platform
free from the rolling and pitching motion of the vessel. From
the cursory view here given of the mode in which I propose to
secure at all times a perfectly steady platform on board ship, the
scientific reader will, doubtless, see many grave difficulties. He
will probably ask, How do you propose that passengers shall pass
from the reeling deck backward and forward at all times into
your quiet, immovable saloon? How can you prevent a pendu-
lous motion of the saloon from being set up by the variation in
position of the centre, which will occur unless your vessel rolls
and pitches at all times actually on a point coincident with the
point where you have established your centre of suspension?
How can you prevent the saloon from being put in motion by
people moving in it from side to side ? My reply to these antici-
pated inquiries is simply that each of them, and many others be-
side, have been presented to my mind in full force during the
elaboration of my plans, and each has been so fully met and pro-
vided for as to offer not the slightest obstacle to that success
which I believe my little ship, the ' Enterprise,' will fully estab-
lish when put to sea, until which time I must beg the critic to
suspend his judgment." Van Nost. Eng. Mag.

ACTION OP SEA-WATER ON THE METALLIC FASTENINGS OF

SHIPS.

We extract from the proceedings of the Institution of Naval
Architects, London, the following short but comprehensive paper
read by William Poole King at a recent meeting. Of course the
facts stated apply equally to all similar fastenings employed in
stationary floating structures and docks:

" The small fastenings of ships are trenails, iron bolts, and cop-
per metal bolts. Each have their advantages and defects.

"The trenail, generally an oak bar of 1^ inch to 1 inch in
diameter, is a cheap fastening. It carries no galvanic influence
from the outside copper on the bottom of a ship to create rust in
the iron work within, and is vulgarly considered the very stamina
and constitution of a ship ; still it must strike every one not
blinded by routine that nothing can be more absurd than to pre-
pare oak timbers square, and cut out all the sap from them, at the
cost of about a crown per foot cubic, and then drill this expensive
timber full of holes from 1| inch to 1| inch wide, in order to

80 ANNUAL OF SCIENTIFIC DISCOVERY.

drive in trenails, and thus take at least half the strength out of
the timber.

"About seaports, where old ships are broken up, many old
timbers are met with in the fields spotted with two large holes in
about every foot of their length ; decay will be observed in all
those holes, caused by the woody fibre being bruised by trenail-
drivinf, for bruised fibre gives nourishment to drv-rot fungus.

^^ ' a */ ^j

Trenails having been squeezed in driving become rotten and
weak, cease to hold the planks to the timbers with firmness, get
bent, and allow a ship to bend and yield throughout its whole
frame ; this is called hogging and sagging.

" Iron bolts and spikes are the cheapest strength that can be
put into a ship. They are the handiest fastenings that a workman
can use ; and a little rusting allows a very small fastening to take
a very strong hold ; in fact, it is everything that could be wished
did it but last without decay.

" In a ship iron bolts are always damp and always rust; rust
frets away woody fibre. Iron bolts, too, always contain a por-
tion of sulphur, which gets converted into sulphuric acid, which
decomposes both the salts always found in oak, and also salt water,
never absent at sea. A ring of decomposed wood surrounds
every bolt; and as the salts and oxide of iron are not prejudicial
to fungus growth, dry-rot fungus takes possession of the ring of
decomposed wood.

"Iron bolts are inadmissible in the bottoms of ships sheathed
with copper ; the salt water acting on so large an extent of cop-
per sends such quantities of electricity through the iron bolt that
the substance of the bolt is carried away, and a vacancy, which
lets in leaking- water, is left in its place.

" Copper bolts and cupreous metal bolts are more expensive
and less strong than iron, but, unlike iron bolts, instead of fretting
the wood in which they are inserted, actually preserve it, for the
verdigris which is formed on the ^copper bolt poisons the dry-rot
fungus. But the copper bolt has the serious disadvantage of
having little hold on the wood through which it passes, and this
little holdfast becomes less after the wood has shrunk with age,
so that the only value of the fastening power of copper metal
bolts is left in the riveted ends of the bolt, and when this end
breaks off, as it frequently does in 9 or 10 years, by getting crys-
tallized, the fastening is of no value at all.

"Trenails are too cheap and useful, as plugs for keeping out
leaking-water, to be given up in wooden-ship construction ; but
the disadvantage of their unwieldy size, boring through and de-
stroying everything, should be reduced as much as possible.
Trenails should be always of the best materials, creosoted to pre-
vent the introduction of dry-rot, kept small in size to prevent
their doing immoderate harm to the worthier parts of the ship,
and driven short to obviate the destruction of timbers, and
floors.

" It is agreed on all sides that iron bolts must never be used in
the wake of copper sheathing. Indeed, to insure the durability

MECHANICS AND USEFUL ARTS. 81

of the structure of a ship iron bolts should never be driven at all,
except in situations where they can be removed and replaced.

** Covering iron bolts with zinc (called galvanizing) does not
protect the iron from rusting, as the acid of the oak surroiihding
the bolt soon dissolves off the zinc cover, and corrosion proceeds
with all its concomitant evils.

" A large quantity of copper metal fastening is now required in
first-class ships. It is expensive. Let us inquire how the great-
est strength, at the lowest cost, can be got from it.

" The screw form, I believe, will be found the strongest and
cheapest method for the use of copper metal. This form gives a
secure hold, and does not injure the wood if the pitch of the
screw be kept high ; that is, the threads of the screw be kept far
apart. I have been accustomed to use screws 7 inches long in-
stead of trenails.

" The bolt is moulded in threads, 3 turns in an inch, cut in a
three-quarters inch bolt of Prince's metal, weighing 13 oz., and
costing 9d. This screwed through a 3-inch plank penetrates the
timbers 4 inches and requires no rivet, as I have tried to start a
deal end from a 4-inch thick piece of oak secured in this manner,
with a strain of 36 cwt. suspended, without having been able to
produce the least separation of the deal from the oak. The
necessity of a through fastening does not exist, as the timber can
be secured to the ceiling by a similar screw to keep it exactly in
place ; thus a long length of metal bolt is saved, the timber but
slightly wounded, and the strength of the frame immeasurably
increased.

" For larger fastenings, such as those for securing timbers and
floors to iron riders, I have used a thread one-eighth inch in
height, placed round outside a seven-eighths inch Prince's metal
bolt, instead of cutting into the body of the bolt, in order to pre-
serve its lateral strength and rigidity. The turns of the screw
are 3 in 2 inches ; a length of 14 inches weighs 3 pounds, and
costs 2s. 6d. I found a strain of 49 cwt. was barely sufficient to
tear this screw through a 3-inch deck deal end, and of course a
lono-er length screwed into oak would require a heavier strain

O O

for its removal.

"Pure copper cannot be cast into a screw for any strength,
and therefore I have used Prince's metal (a mixture of 16 oz.
copper, 3 oz. zinc, and k oz. tin.) This mixture runs into every
sinuosity of the casting-mould, is so tough that it will bend more
than double cold, and I believe will not crystallize and break
when it has grown old."

THE " CAPTAIN."

The following are the particulars and dimensions of the " Cap-
tain," whose recent loss has startled the American as well as the
British public. H.B.M.S. "Captain;" designer, Capt. Cowper
Coles, R.N. ; builders, Messrs. Laird Brothers, Birkenhead, G.
B., 1870.

82 ANNUAL OF SCIENTIFIC DISCOVERT.

Hull 320 feet long 1 ; 53 feet 8 inches beam, 24 feet 9 inches
depth. Tonnage 4,272 B.M. Plating, 8, 7 and 6 inch on hull, 1
and 1 inch on spar-deck, 10 and 9 inch on turrets, with teak
backing. Forecastle and poop-decks 11 feet high, connected by
hurricane-deck 24 feet wide, with iron deck-house between tur-
rets ; 2 25-ton 600-pounder guns. Deck 6 feet above water.
Ship rig, "tripod" masts; 33,000 square feet of canvas; fitted
with 7 boats and 2 steam launches. Engines, 2 pairs trunk en-
gines, 900 N.H.P., surface condensers; 2 screws, 16 feet diameter
each. Speed on measured mile, full power 14.239 knots; half-
power 11,697. Complement of officers and men, about 500.
Journal Franklin Institute.

CONSTRUCTION OF THE " CAPTAIN."

The particulars of the sinking of the " Captain" leave hardly
any doubt upon the faults of construction to which her loss must
be attributed. Although of 1,000 tons less burden than the " Mon-
arch," she had the same heavy armament and thick plating as
that great ship, with enormous iron masts, large spars, and an
unprecedentedly extensive area of canvas. The " Monarch " has a
freeboard of 14 feet; the " Captain," in accordance with the sys-
tem of her designer, was built only 9 feet above the water. Thus
she was in the first place especially liable to heel beyond the cen-
tre of gravity, in consequence of the great weight of the spars,
sails, and turrets above deck, and in the second place particularly
apt to ship heavy seas on account of the lowness of her freeboard.
Being struck by a squall on the port side, she gave a sudden
lurch, so that the tops of the turrets were under water, and the
wind got so powerful a purchase against the under part of the
broad hurricane-deck, which extends from bows to stern above
the turrets, that she was unable to right herself, and was actually
overset by the weight of her masts. She was a more dangerous
vessel than the " Monarch," first, in having disproportionately
heavy spars and too much canvas ; secondly, in having too low a
sea-board ; thirdly, in having a wide hurricane-deck where the
** Monarch " has only a bridge ; fourthly, in carrying too much
weight above the water-line in proportion to her draught. Her
loss seems to settle the principle that low freeboard and heavily
armed turrets, however applicable to vessels of the monitor class
without masts, cannot be safely combined in sea-going vessels
designed to spread canvas. N. Y. Tribune.

WINDWARD GREAT-CIRCLE SAILING.

Mr. J. T. Towson, secretary of the Liverpool Local Marine
Board, read a paper at the meeting of the British Association,
" On Windward Great-Circle Sailing," illustrated by the Transat-
lantic yacht race. Mr. Towson referred to the tables for facili-
tating great-circle sailing constructed by him, and published by
the Admiralty 24 years since, in which he pointed out the value

MECHANICS AND USEFUL ARTS. 83

of windward great-circle sailing. The other modification of this
sailing had been brought into successful use ; but windward sail-
ing, although it appeared most simple, had been generally mis-
understood by practical men. Some had obtained charts having
great-circle routes laid down. If they were driven from this track
by adverse winds, they returned as soon as the wind would, per-
mit them, not perceiving that when they had quitted one great
circle there was another great circle, which was their nearest
route. Others imagined that this sailing consisted in going a cer-
tain number of miles to the northward. The rule was simple.
"Find the great-circle course, and put the ship on that tack
which is the nearer to the great-circle course. In January last
he was invited by Mr. Ashbury to prepare sailing directions for
the Cambria yacht, which he did. These directions were shown
by a chart. It consisted of the great-circle course, corrected for
variation, for every part of the Atlantic it was probable that a
vessel should pass. All the mariner had to do was to ascertain
his approximate position, and then he would find by inspection
how to keep the ship's head by compass. The distance from the
place of destination was also given by another chart containing
the position of both yachts at noon, for each day. Mr. Towson
showed that the " Cambria" saved the race by superior naviga-
tion. This sailing gave the greatest advantage when the distance
of longitude was greatest; and thus the " Cambria" attained all
the advantage that this sailing could afford in the first 5 days,
which was about 110 miles ; afterwards the superior power for an
ocean race possessed by the " Dauntless " prevailed, and reduced
this advantage to a minimum.

THE CABLE SYSTEM OF RIVER NAVIGATION IN GERMANY.

The Frankfort correspondent of the Chicago "Republican,"
writes that the cable system of navigation is, at the present time,
making rapid progress in Germany. This system prevails on
the whole course of the Elbe through the kingdom of Saxony, and
to some extent in the neighborhood of Magdeburg, and its exten-
sion into the interior of Bohemia on the one hand, and to Ham-
burg on the other, is projected, and is expected to be completed
in a short time. On the Danube and its affluents the laying of a
wire cable by the Danubiau Steamship Navigation Company
(Donau-Dampf-schiff farthgeselschaft) is being quickly and ener-
getically prosecuted. The laying of one along the Rhine in West-
phalia has already been completed. It is also intended to make
this fresh invention available for the smaller streams of Ger-
many, as, for instance, on the Saale and the Unstrut, for which
the civil engineer, Opel, of Merseburg, a little while ago, recom-
mended the laying of a wire cable instead of the proposed con-
struction of a towing-path. This system of cable navigation
(either by ropes or chains) is likewise cheaper than the use of
towing-paths, and by this method, also, the possessors of land and
other property on the banks of rivers are spared many inconven-

84 ANNUAL OF SCIENTIFIC DISCOVERY.

iences and unpleasantnesses, which are otherwise unavoidable.
Opel has also shown the superiority which cable steamers possess
over paddle-wheel steamers, since the former cause no ripple.
This system has likewise an advantage in point of economy, since
a steamer working on a chain or rope can make use of from 90 to
94 per cent, of its steam power, while a paddle-wheel steamer can
only use 60 per cent., and even, in case of a strong current, only
30 per cent. As a rule, says the " Bearbeiter," the passenger
boat with a 45 horse-power engine must discontinue its voyage
at high water, while a towing steamer with a 14 horse-power en-
gine holds the navigation open. The cable system of navigation
can go on undisturbed in general so long as the sluices remain in
good working order. While, on account of the inundation, etc.,
the towing-path is inaccessible, such hindrances, on the contrary,
form no obstacle to the steamer on the cable ; or, at most, it only
requires somewhat more coal, if the current be strong. The most
important argument, however, in favor of the introduction of this
system of navigation by means of a cable laid along the bed of the
river lies in the fact that a certain plan can be held ; the failure
of navigation lies principally in this, that the condition of the
weather, or the negligence of the captain, may cause an unpunc-
tual arrival of the cargo at its place of destination. The journey
from Magdeburg to Hamburg, by means of the cable system,
can be accomplished in 3 days, while now often 4 weeks are
required. Tremendous as the difference is, it is, nevertheless,
given as a fact by the above-named paper. There are two diffi-
culties which present obstacles to the introduction of this system,
on some streams ; for instance, on the Rhone and Saone, in France,
this method of river navigation is not possible, because those
rivers convey with them too great a quantity of sand, and thus
clog up the cable. The other difficulty is the sharp bending of
streams, as in the case of the Saale ; but the impediment can be
overcome to some extent by attaching fewer boats to the tugging
steamer. The " Bearbeiter " makes the remark: "If we cannot
succeed so far as to see 30 boats dragged one after the other on
the Saale, as on the Seine, we must, for the present, be satisfied
to transport 3 or 4." On the Oder, also, this system is about
to be adopted ; but this river has, in one place, only a depth of
15 inches ; and it is, therefore, necessary to build the vessel
according to the nature of the stream. On the Elbe, with from
17 to 18 inches of depth, it succeeds well, and th'e investment has
realized from 9 to 12 per cent. In the Saale, at low water, there
is a depth of 28 inches, which, however, soon deepens to from
36 to 40 inches, which is a circumstance much in favor of the above
system.

THE GUATTARI ATMOSPHERIC TELEGRAPH.

This new invention is stated to consist of certain arrangements
and combinations of apparatus whereby ordinary air, compressed
and passed through a tube, is utilized as a means of communicat-
ing intelligence from one given point to another, effecting the

MECHANICS AND USEFUL ARTS. 85

same object as the electric telegraph. The principal portion of
the apparatus consists of a reservoir or air-vessel which is
charged or filled with air compressed to any desired degree
according to the initial velocity or force which it is requisite the
movements of the air employed should possess. A double-action
compression-pump, or any other suitable mechanism, may be em-
ployed to charge the reservoir or air-vessel and to sustain the
pressure to the required degree. The reservoir or air-vessel is
connected by means of a tube or pipe with a writing-apparatus of
any suitable description, and such as are well known and
understood, especially in connection with electro-telegraphy; the
tube or pipe being provided with a cork by which more or less
force may be given to the current of air whereby the writing-
mechanism is actuated. In order to regulate the signals, a gov-
ernor or piston, actuated by hand, is employed, by which pul-
sations or movements of the air in the tube or pipe are transmitted
through a valve which is arranged therein, the currents actuating
a lever connected with the writing-apparatus. For the purpose
of giving or receiving signals, the before-mentioned tube or pipe
is connected with a conducting tube or pipe constructed of any
suitable material, and which is so arranged that communication
can be established between the air reservoir or vessel, and the
writing-engine which is placed at the receiving-station, or vice
versa, by means of stopcocks which are worked by hand. An
indicator is employed to show the force of the current of air pass-
ing through the transmitting tube or pipe. Similar arrangements
are, of course, placed and employed at each end of communica-
tion. By means of this invention it is stated that intelligence and
signals can be transmitted to any distance ; any of the known
receiving and recording instruments capable of being used in
connection therewith b'eing employed. It is obvious that any
number of conducting-tubes may be employed, the requisite cur-
rents or pulsations of air therein being produced as before men-
tioned. The Guattari system claims to be more simple than the
electric system, both in point of construction and continuous use,
for whereas in the latter case it is necessary to use the electric
battery and all its accessories, by the former ordinary atmospheric
air compressed will perform similar functions. It is also claimed
for it that it is free from atmospheric influences, which it is well
known materially disturb the electric telegraph on the occasion
of storms ; and that the tube employed as the medium for conduct-
ing the air would not be subjected to accidents like the ordinary
wires, and would therefore necessarily last longer, and thus prove
much more economical. We understood, also, that it is so simple
that any person may learn in a few hours how to use and work it
with the greatest ease, as compared with the electric system ; it
is calculated that the machinery necessary to work this system
could be produced at about one-half the producing and annual
working cost of the electric system. The Royal Scientific Insti-
tute of Naples has already awarded to Signer Guattari a gold
medal in recognition of what they consider an important inven-
tion, adding a graceful tribute on its presentation to the effect

86 ANNUAL OF SCIENTIFIC DISCOVERY.

that it was the only gold medal which the Institute had ever
awarded. The following experiments were made on Monday,
llth July, 1870 :

1. Transmission by atmospheric compression by means of the
large machine, obtaining answers by impulsion and repulsion,
Signer Guattari having at present but one machine.

2. System of impulsion and repulsion by a naval apparatus,
which may be used with 5 different derivations or branches.

3. Universal telegraphy, namely, dispatch telegrams to one or
more stations at the same time without the aid of the transmitting-
machine, or the necessity of the sender remaining fixed to any
one point. Nature.

THE NEW CABLE BETWEEN ENGLAND AND FRANCE.

The new cable for the Submarine Telegraph Company, to be
laid from Beechy Head to Cape Antifer, near Havre, a distance
of about 70 miles, has been commenced at Mr. Henley's works,
at North Woolwich, and will soon be completed. It forms a
large, massive cable, and will be one of the largest yet manufac-
tured. The core consists of 6 insulated conductors, wound and
served in the ordinary manner; each conductor is a strand of 7
wires, weighing 107 pounds per nautical mile, and insulated with
3 coatings of Chatterton's compound, and 3 of gutta-percha to
the weight of about 150 pounds per mile. The severed core is
sheathed externally with 12 No. O.B.B. galvanized iron wires,
protected with 2 servings of tarred hemp and bituminous com-
pound. The shore ends have a similar core, but are sheathed
with 12 No. 0000 B.B. galvanized iron wires, protected with 2
servings of hemp and compound. This is the first time wire of
such enormous diameter has been used for submarine cables.
Land lines for this cable are being erected between London and
Beechy Head, and Havre and Paris, so that the new line will be
an independent one, and will tend to obviate, if not prevent, the
delays which have frequently occurred in the transmission of mes-
sages between London and Paris, arising chiefly from a pressure
of business. In future any breakage which may take place in
the old and new lines will be quickly repaired, because, under the
authority given lately, the company will conduct repairs with
their own repairing ship, instead of employing a tug as hitherto.
Van Nostrancfs Eng. Mag.

PROFESSOR HENRY OF THE SMITHSONIAN INSTITUTE ON LIGHT-
NING RODS.

In answer to a letter of inquiry as to the best method of erect-
ing and constructing lightning rods, Professor Henry gives the
following instructions :

1. The rod should consist of round iron of about one inch in
diameter ; its parts, throughout the whole length, should be in

MECHANICS AND USEFUL ARTS. 87

*

perfect metallic continuity, by being secured together by coupling
ferrules.

2. To secure it from rust the rod should be coated with black
paint, itself a good conductor.

3. It should terminate in a single platinum point.

4. The shorter and more direct the course of the rod to the
earth the better ; bendings should be rounded, and not formed in
acute angles.

5. It should be fastened to the building by iron eyes, and may
be insulated from these by cylinders of glass (I don't, however,
consider the latter of much importance).

6. The rod should be connected with the earth in the most per-
fect manner possible, and nothing is better for this purpose than
to place it in metallic contact with the gas-pipes, or, better, the
water-pipes of the city. This connection may be made by a
ribbon of copper or iron soldered to the end of the rod at one of
its extremities, and wrapped around the pipe at the other. If a
connection of this kind is impracticable, the rod should be con-
tinued horizontally to the nearest well, and then turned vertically
downward until the end enters the water as deep as its lowest
level. The horizontal part of the rod may be buried in a stratum
of pounded charcoal and ashes. The rod should be placed, in
preference, on the west side of the building. A rod of this kind
may be put up by an ordinary blacksmith. The rod in question
is in accordance with our latest knowledge of all the facts of
electricity. Attempted improvements on it are worthless, and,
as a general thing, are proposed by those who are but slightly
acquainted with the subject.

OCEAN TELEGRAPHY.

Captain Rowett at the meeting of the British Association read a
paper "On Ocean Telegraph} 7 ." He discussed at length the va-
rious properties of the hemp telegraph cable, and to the' satisfac-
tion of the section cleared away the generally received objections
to light cables, by giving several illustrations, which indisputably
proved to the audience how perfectly still was the bottom of the
ocean, and even waters of moderate depths, in which the light
hempen cable would lie in security. He gave also some striking il-
lustrations of the disadvantages of mixing iron wire with hemp, and
made a polite appeal to the numerous ladies present whether their
linen was not seriously damaged by contact with iron. Hemp
was only a coarser kind of the same material, and would be de-
stroyed by the oxide of iron. He maintained also, and gave ex-
cellent specimens of the fact, that hemp can be preserved for any
length of time, and even the salt of the sea preserves the fibre,
whilst on the other hand it destroys iron. Captain Rowett made a
forcible appeal for the adoption of the hemp cable, which would
be half the cost of cables now used, and so do great service to the
millions who desire to have ocean telegraphy within their reach ;
and as there was no possibility of doing justice to the subject at a
meeting of a section of the Association where so much business

88 ANNUAL OF SCIENTIFIC DISCOVERY.

->

had to be done in so little time, he offered to discuss the subject
at length at any time with those interested in the matter. Some
remarks were made, not only of approval, but the opposite views
which had been always entertained were now entirely removed.

ASPHALTE TUBES FOR UNDERGROUND LINES.

Of what material the tubes used to protect and form a subway
for underground wires shall be made, has long been an open
question. M. Collette, of the Netherlands Telegraph Administra-
tion, has submitted the following interesting facts with regard to
the employment of asphalte.

In 1865, a trial line, nearly 3,000 yards in length, was laid in
asphalte tubes in the streets of Amsterdam. These tubes have
each an interior diameter of 3 inches (about 75 millimetres),
and are 7 feet (2 metres 134 millimetres) in length. They are
jointed to each other by the aid of muffles of short pieces of tub-
ing 4 inches in interior diameter, the interstices being run with
bitumen. The laying was executed without the least difficulty.
Only 6 copper wires, covered with a double coat of gutta-percha,
were, in 1865, introduced into the asphalte tubes ; but, 2 years
after, this number was augmented to 25 wires. It is from this
occasion that we have been able to ascertain that the wires with-
drawn from the t<ubes, after having been worked during 2 years,
were in such perfect condition that they were replaced with the
19 new wires. The asphalte tubes, since they were laid, have
3 times been uninjured by accidents which cast-iron tubes would
have been unable to resist, and, doubtless, in breaking, would
have injured the wires.

Five years have elapsed since the laying in Holland of the first
line in asphalte tubes, and, hitherto, scientific men have not been
deceived in their expectations. Also the Netherlands Telegraph
Administration has not hesitated to follow the path dictated by
experience. In January of the present year a length of 10^ miles
of underground lines was laid in asphalte tubes. The maximum
number of wires introduced into tubes, having 3 inches internal
diameter, amounted to 40.

The tubes are chiefly manufactured at Hamburg, and the prices
are as follows : for tubes 7 feet in length and 3 inches in diam-
eter, one dollar per length ; for those having the same length
and 2 inches in diameter, the cost per length, including muffles
for jointing, is about 75 cents. Tubes having other dimensions
have not yet been constructed in Holland.

THE CHASSEPOT AND THE NEEDLE-GUN.

An account is published in the "Birmingham Gazette " of the
two weapons which are in the hands of the belligerents on the Con-
tinent. The " Zundnadelgewehr," or needle-gun, of the Prussian
service, to which the victories of the Prussian arms in 1866 have

MECHANICS AND USEFUL ARTS. 89

been attributed, appears to have been originally patented in
England, as a muzzle-loader, in 1831, by a Mr. Moser, of Ken-
nington. The invention came before its time. Its cold recep-
tion in England drove the patentee to seek foreign patronage for
his novelty, and Prussia was lucky enough to appreciate and to
adopt the new weapon. Dreysa, a gunmaker of Sommaler, ap-
plied the breech-loading principle to Moser's patent, and thus
amended, the arm 10 years later was in 1848 introduced into the
Prussian service. The principle, briefly stated, is the driving of
a pointed piston or "needle," by the action of a spiral spring
(such as is used in the manufacture of children's toy-guns) into a
small case of fulminate, contained in and situated between the
powder and the bullet of a single cartridge. In the action of
opening the breech, the spiral spring is set by the trigger, and
thus the trigger, when pulled, releases into operation the spiral
spring, which, in its turn, forces the needle into the cartridge
and lires the piece. Upon this oldest form of the Prussian needle-,
gun improvements have been made, the chief effects of which
have been a reduction of the mechanism of the needle of 1848,
and a general lightening of the entire piece. None of these
alterations, however, have touched those two apparent evils in
the whole form of this arm which militated against its adoption
by England in 1850. These are the positions of the fulminate in
the interior of the cartridge and the looseness of mechanism, in-
volving possibility of the escape of gas round the needle and at
the base of the plunger. To -these two particular points France
mainly devoted herself in seeking a superior needle-rifle to that
of Prussia. In the Chassepot such an improved arm has been
found. A triple wad of vulcanized India-rubber, placed round
the axis of the plunger, with a steel plate, forms a cushion to re-
ceive the force of the rebound and is intended to render the breech
gas-tight, but has been found in practice only partially adapted to
that object. An ingenious arrangement of notches on the outer
girder of iron, before described, enables the gun to be placed at
half-cock. The needle is lighter and smaller than in the Prussian
gun, and, above all, the cartridge contains its fulminate at the
base of the powder, instead of at the base of the bullet. A vac-
uum left when the gun is charged, between the base of the car-
tridge and the front of the plunger, is intended to effect the com-
bustion and removal of an} T portion of the cartridge-case that may
remain after firing. As compared with the Prussian gun, this
weapon possesses, besides the specific improvements mentioned,
other advantages of superior manufacture and finish. Its car-
tridge, besides admitting the altogether different principle of fir-
ing, contains a larger charge of powder than the Prussian car-
tridge, with a smaller bullet, which leaves a manifest advantage in
carrying to the French weapon; and the fact that the Prussian
bullet is purposely made so small as not to touch the barrel in its
passage, while the French bullet is of the ordinary size to fit the
rifle-barrel, would point to the conclusion that the Prussian
marksman is at a disadvantage over the Frenchman in respect to
his arm. The number of times of firing per minute is about the

90 ANNUAL OF SCIENTIFIC DISCOVERY.

same in both cases. The cost of the French weapon considerably
exceeds that of the Prussian, and the Chassepot is, in a'ddition, a
more difficult gun to make. To all the comparative information
which has been published about the French and Prussian guns
must be added the following from the " Journal du Peuple : " At
500 metres the Prussian weapon gives only negative results, while
at 1,000 the Chassepot, in the hands of good marksmen, hits the
target with great force. We call attention to this point, for in
the war of large bodies of sharp-shooters (the only system which
we ought to adopt), an arm which is not reliable over 500 metres
cannot reach the reserves of tlie first front, which escapes the
effect of the enemy's fire. The drawbacks of large bullets have
been noticed, the principle being this, that with needle-guns the
firing is rapid, and, therefore, a great amount of powder is burnt ;
consequently, the cartridge-box must be well stored. Now there
is in the weight of ammunition allotted to a foot soldier a total
.which cannot be exceeded, namely, 10 pounds. What will hap-
pen ? With that weight of cartridges the Frenchman will have
twice as many shots to fire as the Prussian. Nothing is more dif-
ficult than to replace, during fire, the ammunition by a fresh dis-
tribution. Thus, the retreat of a division may depend on its
finding itself in face of an enemy which has still 20 or 30 car-
tridges a head to fire. It will be seen that the winning of a battle
may depend on the projectile adopted. Van Nost. Eng. Mag.

PROJECTILES.

An extremely satisfactory result, as far as the navy is con-
cerned, was lately obtained at Shoeburyness. A target repre-
senting a portion of the deck of an iron-clad ship, protected by 1-
inch iron plates, was fired at by the 9-inch muzzle-loading rifled
gun, the projectile being a Palliser shell, the charge the full batter-
ing one of 43 pounds, and the distance 100 yards. The target
was so arranged that the projectile struck at an angle of about 8 de-
grees from the horizontal, so as to represent the angle of incidence
of a shot fired direct at about 2,000 yards, or that of a projectile
fired at 100 yards from a higher level ; such, for instance, as that
of the " Monarch's" battery as compared with the "Captain's."
It was found that at this angle the projectile did not enter the
ship, but, after ploughing up the woodwork of the deck, rico-
chetted off it, and went away screaming and whistling up into the
air until lost from sight. One of the disadvantages urged against
a low freeboard is thus disposed of as far as 9-inch guns are con-
cerned. The " Monarch," however, is armed with 12-inch guns,
and it would be interesting to ascertain whether the above results
would hold good in the case of the larger calibre. It seems de-
sirable also to ascertain the actual angle at which a projectile
fired horizontally will penetrate a ship's deck protected with as
much iron as is admissible in its construction. Ships' decks may
often be subjected to a plunging fire from elevated batteries such
as those on Stradden Heights or Gibraltar. Van NostrandSs Eng.
Mag.

MECHANICS AND USEFUL ARTS. 91

PRUSSIAN NEEDLE-GUN.

The alteration of the Prussian needle-gun has been sanctioned
by the king, in consequence of which 2 or 3,000,000 of rifles
in the possession of this government will be remodelled. The
improvements introduced aim at simplifying the loading, and
increasing the force and range of the ball. For this purpose the
caoutchouc ring of the Chassepot has been adopted, which, help-
ing to close the breach by spontaneous action, renders it unneces-
sary to press the valves tightly down. In addition to this the
weight of the ball has been reduced from 31 to 21 grammes,
which, with the charge remaining at 4.9 grammes as formerly,
considerably augments the propelling force. To fit the reduced
ball for the old barrel the zund-speigel has been proportionately en-
larged, a proceeding the practicability of which was proved by a
similar alteration, adopted some time ago, and further attested by
a year's experiments with the weapon in its present latest form.
On the needle-gun being first taken into favor, in 1841, it had a ball
of 15.43 millimetres, but the heaviness and consequent want of
speed observable in the missile caused it soon to be reduced to
13.6 millimetres, which size has now been further diminished to
12 millimetres. The total weight of the new cartridge is 32
grammes, instead of 40, as heretofore, so that the soldier will
henceforth carry 95 instead of 75 cartridges, without experiencing
an additional burden. Besides this, the needle is now made to
move in a narrow hole, into which it fits exactl} 7 , instead of the
wider one of the old gun, and a piece of oiled paper is placed at
the bottom of the cartridge to clean the needle after each dis-
charge, and serve some other purposes of minor importance.
Van Nostrand.

PHOTOGRAPHY APPLIED TO MILITARY PURPOSES.

A writer in the " Nature," of July 21st, dwells upon the use
made of photography by the English military authorities.
Three establishments have been organized in connection with
the army, in which photography is extensively practised.

Pictures are taken to illustrate the positions taken by a soldier in
different drill systems ; of pack mules, to illustrate the manner of
packing for the benefit of the India armies; in short, photographs
are used whenever mere descriptions would be prolix and am-
biguous.

Great use is also made of this art in recording the results of
experiments in gunnery ; these photographs are made by the
carbon process. Editor.

NEW ARMS.

Sir Joseph Whit worth, Bart., at the meeting of the British As-
sociation, had had diagrams prepared to illustrate the Chassepot,
the Prussian, the Enfield, and the Whit worth bullets. The Chasse-

92 ANNUAL OF SCIENTIFIC DISCOVERY.

pot was 2.44 calibre, the Prussian 2.01, the Enfield 1.93, and
the Whitworth 3.00. At an elevation of 58 minutes, the range of
the Chassepot was 500 yards, the Prussian 206 yards, the Enfield
295 yards, and the Whitworth 345 yards. The two most
important elements in long ranges were a full charge of pow-
der and sufficient longth of bullet. In both these respects
the Enfield ammunition was sadly deficient, and he had been
urging the War Office authorities ever since 1857 to substitute the
45-inch bore. The velocity of the Chassepot bullet was much
greater at the commencement of its flight and much less at the
end ; thus, its penetration was comparatively small at long

ranges.

Mr. E. J. Reed, C.B., said it appeared to be universally ad-
mitted that a small-bore rifle was a long-range weapon ; and that
if troops were armed with a large-bore or short-range weapon
they would be subjected to a murderous and destructive fire be-
fore their rifles could be brought within range of the enemy
armed with the small-bore rifle. It was clear that the small-bore
or long-range rifle was the only effective weapon for military
warfare to make that warfare effective.

BALLOONS FOR WAR PURPOSES.

The experiments made at Woolwich by balloons inflated at the
Royal Arsenal Gas Works have, on the authority of the London
" Artisan," shown that a height of 100 fathoms, at a horizontal dis-
tance of 600 fathoms from an enemy, would enable the observers
to secure a wide expanse of view. The balloons with which ex-
periments were made at Woolwich were held by 2 new cords
fastened to the network, and terminated at 2 different points
on the ground, to give greater stability to the balloon, and to pro-
vide against one cord snapping, or being cut by the enemy's fire.
By the new system of military telegraphy for field service, and
by means of wagons at present being placed in store in the Royal
Arsenal, lines of telegraph can be carried through the air from
the earth several miles distant. The wire can be paid out as fast
as the balloon travels, so that if a captive balloon should break
away, communication could be kept up with it for 6 miles ; or
2 or more balloons can be sent up, and kept in telegraphic com-
munication with each other by means of similar lines, so that tele-
graphic operations can be made from the balloon to head-quarters,
and thence to the base of operations.

By means of these new military telegraphic appliances the most
rapid intelligence, and consequent speedy word of command, can
be given. In sieges, war balloons are useful in giving informa-
tion of depots, points of attack, batteries, inner intrenchrnents,
the explosion of magazines in marshes, to spy out ambuscades
that may be in waiting, to rally columns, and to telegraph points
of assembly on attack. The observing officers were enabled to
survey an area of 30 square miles. It was found that by prac-

MECHANICS AND USEFUL ARTS. 93

tice great skill can be attained in judging of distances, and the
relative position of masses of troops ; while more minute details
could be subsequently obtained at leisure by field-glasses as to the
position of mountain gorges, passes, limits of woods, and the
course of streams. The trials hitherto made have been chiefly
carried on by professional aeronauts with hired balloons ; and it
is believed that the British Government have at the present time
no war balloons in store.

The result of the observations of Captain Brackenbury and
Captain Noble, sent out from Woolwich on behalf of the English
Government to the respective seats of war, together with trials
and other sources of information, will, it is believed, result in
war balloons being manufactured in the Royal Arsenal, and that
officers of royal engineers, from generals downwards, will be
trained in their use.

THE GREAT SUBMARINE BLAST IN THE HARBOR OF SAN

FRANCISCO.

It is well known that extended preparations have been making
for several months, under the direction of Col. Van Schmidt, C.E.,
to remove what is known as Blossom Rock, the most dangerous
obstruction in the magnificent harbor of San Francisco.

That so important an engineering work should have been
brought to so successful a conclusion reflects great credit upon
the skill of Col. Van Schmidt, and the particulars of this feat of
submarine blasting will be interesting to our readers.

A careful survey of the rock was made at the outset in order to
ascertain the irregularities of its surface. This being done, and
plans being drawn, a coffer-darn was constructed around a por-
tion of the rock to be removed, and moored by means of a scow
loaded clown with heavy stones.

The water was stopped from entering the dam by sand-bags
placed about its base, and an iron turret was erected within it.
This turret was then sunk 3 feet into the rock and cemented fast.
A platform 56 feet long and 20 feet wide was then erected, and an
engine and hoisting apparatus placed thereon, together with a
building in which to lodge the workmen and prepare their
meals.

The plan of excavation was to scoop out the interior of the
rock, leaving an external shell of sufficient thickness to resist the
pressure of the surrounding and superincumbent water, and
finally to shatter and scatter the shell by blasting. The thickness
of the shell was about 6 feet.

Pillars of rock were left- to sustain the shell, and when these
were removed they were replaced by timber supports. The
space excavated measured in the clear 140 by 50 feet, and it is
estimated that about 40,000 cubic feet of stone were taken out.
The shape of the surface of the rock was nearly oval, but for a
distance of about 120 feet it sloped very little. The height of the
highest pillar inside was 29 feet, and the lowest 4 feet. The

94 ANNUAL OF SCIENTIFIC DISCOVERY.

stone was a porous sandstone. When struck with a hammer it
fell to pieces readily, and revealed a series of seams running
through it. There was no mixture of slate or granite, or any of
the harbor kinds of stone in it.

Of the 23 tons of powder used, about half was contained in
English ale casks, double-coated with a heavy pitch varnish inside
ancT outside so as to be water-proof. The other half of the pow-
der was in 7 boiler tanks of wrought iron, firmly bolted, the larg-
est measuring 8 feet in length and 2 feet in diameter. The bar-
rels were placed close to the side of the excavation, near the
junction of the arch or roof with the floor, so as to blow away
the arch from the lowest point of the excavation reached. They
were placed resting on their sides. The 7 boilers were laid
through the centre of the chamber, the largest in the middle,
where the roof was highest. This disposition was made to
equalize the force on each part of the rock. A perforated piece
of gas-pipe, 2 feet in length, charged with fine gunpowder, ran
into each barrel from the end, with a piece 6 feet long into the
boilers, charged in the same way. These different tubes were
connected with insulated electric wires, which passed from one
barrel to another, the end in each tube consisting of a fulminat-
ing cartridge.

The insulated electric wires connecting the barrels were encased
in gutta-percha. When the powder was arranged in the excava-
tion, and the connections made secure, this wire was drawn up
through a tube in the shaft, and placed on board a bark situated
about~l,000 feet from the rock. Here it was connected with an
electric battery. The coffer-dam was then removed, and the
water permitted to fill up the excavation, and so act as a tamp-

ing.

It being understood that the blast would be fired on the 23d of
April, a very large concourse of people gathered to witness it.
Everything appears to have worked properly, and the explosion
threw a column of water and rock, 100 feet in diameter, 100 feet
into the air. It is believed the operation has been entirely suc-
cessful, and that the rock will give no further trouble. ^

The method employed seems very ingenious, and is, so far as
we are aware, entirely novel. Scientific American.

REMOVAL OF THE HELL-GATE OBSTRUCTIONS.

The work of removing these noted obstructions to navigation is
continued unremittingly night and day. Eight "galleries" or
chambers have been commenced. These run in various directions
under the reef, all converging to a common centre at the point
of beginning. They are named after distinguished men. Those
furthest advanced are " Grant," "Sherman," "Humphries." They
all front the great excavation, which is GO by 100 feet in size, and
30 feet from the mean low-water mark to the floor line. " Grant"
gallery has been pierced to a distance of 32 feet directly under the
most formidable spur of the reef. These tunnels are to be ex-

MECHANICS AND USEFUL ARTS. 95

tended a distance of 200 feet, and are from 8 to 10 feet in diame-
ter. The rock is very hard mostly gneiss. The blasting charges
are one-quarter, one-half, 1 and 2 pounds respectively, contained
in pasteboard tubes well wrapped in glazed gutta-percha cloth,
tarred at the ends, with safety-fuse, all water-proof. 30 or 49 of
these are discharged at the same time, a gong being previously
sounded to draw off the workmen.

Huge logs, interlaced with iron bands, form " curtains," which
are hung at the opening of each tunnelling to prevent the de-
tached rock from being hurled into the air without. The force is
so terrific, however, that these ponderous curtains are often
swung out 8 or 10 feet. Great steam derricks elevate the refuse,
and steam pumps lift out the water. Daily observations are
taken to guide the work. A miniature levee keeps off the water
on the river side. A temporary platform extends out over the
reef, from which a fine view of the wild, rushing tides is afforded.
Even when but about a depth of 2 feet of water is flowing over
the " hog's back," its force is so great as to sweep a strong man
instantly off his feet. This gigantic enterprise must proceed very
slowly, and require years for its successful completion.

EXPLOSIVE POWER OF NITRO-GLYCERINE.

"We condense from the "American Chemist" the following
upon the above subject :

A measure containing 1 cubic foot will hold 796 ounces of
blasting-powder, and 997.1 ounces of water; or, in other words,
the specific gravity of blasting-powder, as it is used, is about 0.8.
This, of course, takes in the interstices, which are filled with air,
but as we do not use the powder in a solid lump, this is, for prac-
tical purposes, the specific gravity of blasting-powder. Now, the
specific gravity of nitro-glycerine is 1.6. Therefore, bulk for bulk,
if the explosive power were the same in a given mass, as pre-
pared for blasting, the nitro-glycerine would have twice the
power.

In reality the following are the volumes of gas generated by
each respectively in explosion :

One volume of powder, which is considered as most effective,
produces :

Carbonic acid gas 221.4 vols.

Nitrogen, 74.6 vols.

Of another kind of powder, which explodes with the gases at a
lower temperature, one volume produces :

Carbonic oxide, 391 vols.

Nitrogen, G6 vols.

One volume becomes 457 vols.

9G ANNUAL OF SCIENTIFIC DISCOVERY.

One volume of nitre-glycerine produces :

Carbonic acid gas, 469 vols.

Water at 100 C., 554 vols.

Oxygon, 39 vols.

Nitrogen, 236 vols.

One volume becomes 1,298 vols.

These volumes are given at the temperature degree C. ; at
the temperature of explosion, they will be about 5 times greater,
or about 10,607 times the original volume of the explosive, or
about 10 times as large a production of mixed gases for the nitro-
glycerine as for the gunpowder which produces mixed gases in
largest amount.

Still 13 times is claimed by the advocates of nitro-glycerine. If
this is so, the discrepancy between the temperature of the explo-
sion must be greater than here assumed.

UTHOFRACTEUR.

Analysis shows that " Lithofracteur," as well as dynamite,
consists of a mixture of a silicious base with nitro-glycerine. The
proportion of glycerine appears to be that which the base can
take up without becoming sensibly moist. Dresdner Gewerbeve-
reins-Zeitung.

In the " Centralblatt," of Oct. 15, can be found a discussion of
the merits of the above. Its exact composition appears to be

Nitro-glycerine, 52

Silicious base, : 30

Coal, 12

Saltpetre, 4

Sulphur, , 2

DUALIN.

Professor Mowbray, who superintends the manufacture of nitro-
glycerine at North Adams, for the Hoosac Tunnel, writes to the
" Springfield Republican " in regard to the explosion at Worces-
ter, Mass. He finds that dualin consists of 60 per cent, mono-
nitro-glycerine and 40 per cent, of sawdust.

The mono-nitro-glycerineis exceedingly unsafe to manufacture,
to use, or to transport; it is not nearly as destructive as the tri-
nitro-glycerine and yet is far more dangerous to handle. There
are 3 different nitre-glycerines. Of these 2 are the most dan-
gerous and not as powerful as the third, which is not dangerous
but very difficult to explode, and when exploded is 33 per cent,
more powerful in its effects than either of the 2 others.

Trials were made with dualin at the Hoosac Tunnel, and were
complete failures. Only about 50 per cent, of results as com-
pared with the nitre-glycerine in use at the tunnel were obtained,

MECHANICS AND USEFUL ARTS. 97

and the miners were asphyxiated by the cyanogen given off.
Editor.

Dualin is a brownish-yellow powder, similar in appearance to
Virginia tobacco. In the open air it burns without an explosion,
and in a confined space it acts like gunpowder.

It is proof against shocks, it does not decompose, or bake to-
gether, can be readily put into cartridges, and can be used as well
in warm as in cold, in dry as in wet, places. Its strength is 4 to
10 times greater than the common powder, and greater than that
of dynamite.

Dualin consists of cellulose, nitro-cellulose, nitro-stdrJce nitro-
mannit and nitro-glyceriue, mixed in different proportions accord-
ing to required strength.

We believe that dualin, with its present quality and with its
present price, has every prospect of being useful in mining opera-
tions, especially in coal-mining, when with its great, but yet not
too quickly, working power, it can rival powder. Bergeist.

In the " Centralblatt," of July, can be found a long account of
this new explosive, taken from the "Deutsche Industrie Zeitung*"
Editor.

COMPARATIVE EFFECTS OF GUNPOWDER AND GUN-COTTON.

A number of experiments have been recently carried out by the
officers of the Royal Engineers at Chatham to test the comparative
effects of gunpowder and gun-cotton in various operations. The
experiments were all made under the direction of Colonel W. O.
Lenox, C.B., Y.C., Instructor in Field Fortifications at the school
of Military Engineering, assisted by a number of other officers.
The experiments were attended by a large muster of officers of
the garrison, besides those of the engineering corps, and also by
Major-General J. L. Brownrigg, C.B., the commandant of the
garrison; Colonel W. Pray, Colonel Graham, C.B., Y.C., Colonel
Fiser, Colonel Lovell, commanding Royal Engineers ; Colonel the
Hon. H. F. Keare, Deputy Adjutant-GeneralRoyalEngineers ; Colo-
nel Clarke, etc. Mr. F. A. Abel, chemist to the War Department,
was also present, and assisted in some of the experiments with gun-
cotton. The experiments commenced with explosions of gun-
powder and gun-cotton directed against a double stockade of
balks of timber 14 inches square, 3 feet 6 inches apart, and sunk 3
feet in the earth, each line braced together by strong cross-pieces.
A charge of 200 pounds of gunpowder, in bags merely laid at the
foot of "the stockade, untamped, was first exploded. It forced a
large gap in the front stockade, but, though partially shattered,
the second row of timber would have presented a formidable ob-
stacle to an attacking party if defended by a few resolute men.
Portions of the timber were hurled through the air to some dis-
tance. A charge of 80 pounds of gun-cotton was next laid in
bags at the foot of the stockade, some distance from the former
explosion. This also was untamped. It was fired by a detonat-
ing fuse. There was a terrific explosion, and an almost perfectly

o

9

98 ANNUAL OF SCIENTIFIC DISCOVERY.

clear breach was made through both rows of timber, practicable
for an attacking party to get through. The effect was very much
superior to that of the 200 pounds of gunpowder. Immense
pieces of timber were hurled through the air to a great distance,
mostly in the rear of the stockade. Not so wide an extent of
timber appeared to be shaken as by the first explosion, but the
work was more completely done ; the results, indeed, were extraor-
dinary. Experiments were also made by exploding discs of
gun-cotton against single balks of timber, to show what effect
would be produced if timber bridges had to be destroyed. Four
balks of timber, about 16 inches square, were sunk in the ground
some feet apart, in a square, and braced together by thick pieces
of plank. A " necklace " of small discs of gun-cotton was formed
(about 68 in number) ; this was doubled and placed half round
one of the timbers. The explosion of this string of discs tore away
the wood for some depth, 4 inches or more on one side of the balk,
but did not break it, though the massive timber was much rent.
Three or four larger discs were then exploded on one side of the
timber, and tore out a large portion of the wood. A single " neck-
lace " of small discs, 65 in number, and weighing 2 pounds, was
then placed round another balk, quite encircling it. When ex-
ploded this tore out the wood all round to some depth. Then 12
of the larger discs, weighing 4 pounds 2 ounces, were hung on
nails on three sides of the timber, and exploded. The explosion was
very powerful, and the large balk was cut in two ; snapping off
where the gun-cotton had been attached, but falling on the side
where there had been no discs and partially splitting on that side.
The spectators cheered at this decisive proof of the value of gun-
cotton for this special purpose. All these experiments appeared
to be very satisfactory. At that part of the lines in front of St.
Mary's Barracks, a number of mines and galleries had been exca-
vated and charged with gunpowder or gun-cotton. One mine
had a charge of 500 pounds of gunpowder ; a second similar mine
was charged with 200 pounds of gun-cotton. Two smaller mines
were charged respectively with 21.6 pounds of gunpowder and
8.6 pounds of gun-cotton. These mines were successively ex-
ploded by means of an electric current. In the larger mines the
powder appeared to be the most effective agent. In the explo-
sion of the 200 pounds 1 charge of gun-cotton, a peculiar effect
was produced ; first, there was the eruption of brown clay and
smoke, and then a large flame, produced by the ignition of the
gaseous products of the explosion. The officers then proceeded
to the old Engineer Depot, near St. Mary's Convict prison, and
walls which are to be removed were experimented upon ; they are
18 inches thick ; charges of gun-cotton ranging from 2 pounds to
3 pounds were exploded against these walls, with satisfactory
results, making breaches in them. The officers then returned to
the scene of the mines, where two long galleries had been pre-
pared, one charged with 240 pounds of gunpowder, the other with
96 pounds of gun-cotton. These charges were exploded. The
object was to ascertain if it is practicable to form trenches in this
manner, instead of throwing them up while exposed to the en-

MECHANICS AND USEFUL ARTS. 99

emy. It was thought by some officers that the explosion would
throw the earth up on either side in such a manner as to form a
trench ; but the result was not so ; the earth was thrown up in a
mass, and no trench was formed in which men could get under
cover at once. The experiments were of great interest and
highly satisfactory. Van. Nos. Eng. Mag.

COMPARISON OF NATURAL AND ARTIFICIAL ICE.

The French company Messageries imptriales, wishing to ascer-
tain what kind of ice would be preferable for their vessels navi-
gating the Suez Canal, caused experiments to be made, under
identical circumstances, with several varieties, with the following
results : Time required to melt 200 pounds of ice :

Natural ice of Switzerland, 107 hours.

" " Norway, 115 "

" " Massachusetts, 138 "

Artificial ice, Carre's machine, , 130 "

" " Tellier's machine, 144 "

If these experiments were conducted with accuracy, they would
seem to prove that artificial ice would have the preference over
the natural production of our lakes and rivers for transportation
on shipboard, and for refrigerating mixtures. One series of ex-
periments is scarcely sufficient to settle a question of this impor-
tance.

THE TELLIER ICE-MACHINE.

The manufacture of ice by artificial processes is steadily gaining
ground and favor. During the last summer it has received a
powerful impulse from the exorbitant prices asked and un-
willingly paid for ice in this and southern cities, in which this
article has become so much a necessity that people will pay
almost any price rather than be deprived of it. In this city its
price reached 2 cents per pound before the close of summer, and
in one southern city, we are informed by a correspondent, it
reached 5 cents per pound.

It is not probable that such exceptionable prices can be main-
tained during ensuing seasons; but even at the prices at which
we may reasonably hope to purchase ice, or at least such prices
as must be demanded for ice shipped to southern towns, it is now
demonstrated it can be produced artificially at large profits and in
any required quantity.

Two machines have been brought prominently into public
notice, each employing the same volatile material as an absorb-
ent, conveyer, and radiator of heat, and being in some sort
rivals in the effort to secure public favor. We allude to those
known as the Carre and the Tellier ice-machines. The volatile
agent in both is generally ammonia, and, though differing widely

100 ANNUAL OF SCIENTIFIC DISCOVERY.

in detail and cost of construction, they employ the same general
principle in the conversion of water into ice.

To the general reader it may be well to state here that the fun-
damental principle upon which machines of this kind operate is the
absorption of heat from surrounding bodies by an expanding
substance, the conveying of this heat to some other absorbing
body, into which the heat is caused to radiate by the condensation
of the conve}'ing substance by mechanical compression, the pass-
ing back of the conveying body to extract another modicum of
heat from the body to be cooled or frozen, and so on till the
desired degree of refrigeration is reached.

It is a physical law with which perhaps some of our readers
are not familiar, that the capacity of any substance for heat that
is, its power to absorb heat, and hold it in the latent or insensible
state increases with its expansion and decreases with its con-
densation. A substance which at ordinary temperatures is a
permanent gas will, when compressed, become sensibly heated ;
the latent heat which it holds, under ordinary circumstances, being
rendered sensible by condensation. If while in this state the
sensible heat be taken up by some other substance and conve3 T ed
away, the gas in expanding will seize the heat from surrounding
bodies, thus reducing their temperature. The gas, on being
again compressed, will yield this heat to any substance having a
lower temperature. The proportion of heat absorbed during
expansion, and emitted under pressure, increases with the degree
of alternate condensation and expansion.

Ammonia, which is a gas of ordinary temperatures, becomes a
liquid under a pressure of from 9 to 13 atmospheres, according
to the temperature of the surrounding air, emitting a large
amount of heat in so doing, which amount must be restored to it
before it can expand to its original volume. On this account it is
admirably fitted for use in refrigerating apparatus.

The Tellier machine, besides differing much from the Carre
machine in matters of detail, differs from it in its action, the con-
densation of the ammonia being in the latter effected entirely by
mechanical compression, while in the former the strong affinity
of ammonia for water is used in the collection of the gas, the
latter being separated from the water again by distillation.

In the Tellier machine the liquefied ammonia is first received
into a strong cylinder, for convenience of transportation. This
cylinder being attached to suitable pipes connected with the
machine, the opening of certain cocks allows the ammonia to
escape into a distributer or a cylinder connected by pipes with the
congealer. The congealer is a square box divided into compart-
ments by hollow metallic partitions, the compartments being tilled
with the water to be frozen, or they may be filled with a solution
of chloride of calcium or salt water, in which are placed metallic
moulds containing the water to be frozen. The latter is most con-
venient when very large cakes are desired.

The ammonia, passing from the distributer into the hollow metal-
lic partitions of the congealer, expands into a gas, absorbing in its
expansion a large amount of heat from the fluid contained in the

MECHANICS AND USEFUL ARTS. 101

compartments. It is then drawn from the congealer by the pump
and forced back again into the distributer in a condensed form.
During the process of condensation it gives off its heat to water
surrounding a coil through which the gas is passed on its way to
the distributer, from which it again passes to the congealer, and
so on, being used over and over without material loss.

It will be obvious that any other volatile liquid besides ammo-
nia might be used in the same manner as a conveyer of heat.

It is further obvious that by replacing the hollow partitions of
the congealer by a series of bent pipes, air might be cooled if
forced through the series of pipes by a fan. This is precisely
what is done with an apparatus made by the proprietors of the
Tellier machine, the cool air being supplied to vaults and rooms
used for preserving fruits, packing meats, etc., and for purposes"
of ventilation in churches and public buildings in hot weather.
There is, we are informed, no difficulty in reducing and main-
taining the temperature to any desired point down to 32 Fah.,
and the air, being supplied in a dry state, is much better adapted
to keeping fruits and meats than when charged with vapor from
its passage through ice. Scientific American.

NEW SUGAR-REFINING PROCESS.

In the sugar-house of Messrs. A. Sommier & Co., of Paris,
200,000 pounds of raw sugar have for a year past been daily
refined according to a process invented by Boivin and Loiseau.
The process is founded upon the use of a new body, the sucrate
of the hydro-carbonate of lime, which the inventor employs for
the purification of raw sugar instead of blood, bone-black, etc.
For the preparation of this compound, milk of lime is made from
the waste sweet liquors of the refinery, and enough syrup added
to give the mixture 20 Baume. This is well agitated and run
through a cooler until the temperature sinks to 68 Fah. From
the agitators the liquid flows into vats, where it is partially satu-
rated with carbonic acid ; the gas is passed through until the
desired precipitate of su^ar, lime, and carbonate of lime settles
as a gelatinous mass. Alter the purifying agent has been thus
prepared, it is applied in the following manner :

The raw sugar is dissolved in a c}'lindrical pan, similar to a
vacuum pan, under diminished pressure. Revolving buckets
carry it into receivers over the boilers, and from these it is per-
mitted to flow into the boilers, where it conies in contact with the
sacro-carbonate of lime previously introduced, in a quantity pro-
portional to the percentage of raw sugar. They generally take
about 650 gallons of the gelatinous sucro-carbonate to 8,000
pounds of sugar. Water is added if necessary ; the whole is
boiled, and in this way the solution and clarification are simul-
taneously accomplished. One great advantage of the operation
is that when syrup is boiled in presence of lime, ammonia is
evolved, all glucose is decomposed, and anything likely to pro-
duce fermentation is destroyed.

102 ANNUAL OF SCIENTIFIC DISCOVERY.

The syrup from the boilers is filtered, the excess of lime sepa-
rated by carbonic acid, and it is further concentrated and finished
in the usual manner. The slimy residues and precipitates are
squeezed out in filter presses until they contain no trace of sugar,
and can be thrown away. The wash-water is used in the prepa-
ration of new material. The advantages of this new process are,
that it does away with the use of blood, which is offensive, diffi-
cult to obtain, and the soluble constituents of which are finally
concentrated in the molasses.

It also yields greatly improved products, which are brighter in
color, and better in grain. The third crystallization of this
process is better than the second in the old way. The expense
is, if anything, less, certainly not more. The process has been
patented in the United States.

APPLICATION OF DIFFUSION IN SUGAR-REFINERIES.

Abbe Moigno states that in the years 1869-70 the number of
sugar-houses in which the principle of diffusion or dialysis was
employed for refining sugar was 82, and that 31 additional works
are in process of construction; so that in 1871 there will be 113
refineries in which practical application will be made on a large
scale of Graham's important law. The crystallizable sugar passes
through membranes, while the impurities, being uncrystallizable,
are retained in the tank where the original solution was made.
The fact that so many large houses employ this method would
seem to indicate its entire practicability.

PHOTOGRAPHY ON WOOD.

Anthony's ' Photographic Bulletin" gives the following process
by A. J. Searing for photographing on wood for engraving pur-
poses :

" The block on which the picture is to be made is first dampened
with water, then whitened with enamel, rubbed from the surface
of good enamelled visiting-cards. Rub gently, removing only
the enamel, after which it is brushed smooth with a moderately
stiff brush, from right to left and up and down, making a smooth,
even, and very thin surface. Allow this to dry, after which it is
flowed with a solution of albumen, made with the white of 1 egg
and 16 ounces of water, dried by heat or allowed to dry spontane-
ously. Now coat it with another albumen solution made as fol-
lows :

Formula No. 1. White of 1 egg; water, 4 ounces; chloride
of ammonia, 40 grains. Beat the whole to a thick froth. Allow it
to subside, then decant or filter through a fine sponge placed in a
glass funnel. Pour a sufficient quantity on one corner of^the
block to cover it, when spread around with the aid of a one-ninth
or one-sixth glass (using the edge) . Allow the surplus solution
to drain back into the bottle. Dry by a gentle heat.

Formula No. 2. Ether, 1 ounce; alcohol, 1 ounce; gun-

MECHANICS AND USEFUL ARTS. 103

cotton, 8 grains; nitrate of silver, 30 grains; dissolved in as
small a quantity of water as possible, and allowed to settle for a
few days, protected from the light. Flow the salted block with
formula No. 2, in the dark room, and dry it by a gentle heat. It is
now ready for exposure under the negative. A porcelain print-
ing-frame, or any other suitable method, may be used to print it.
After printing, formula No. 2 is removed from the surface of the
block by dissolving it in ether and alcohol, assisted by rubbing
gently with a soft sponge. The picture can now be toned and
fixed in the ordinary way, or fixed and toned at one operation,
by the hypo and gold bath. After being allowed to dry, it is
ready for the engraver.

THE OXYGEN LIGHT.

According to the " Opinion Nationale," Paris, the new Prefet
de la Seine has definitively authorized the Tessie du Motay Com-
pany to lay their underground communications in the city of
Paris for illuminating with oxygen gas.

A system of pipes will connect the oxygen works of Pantin
with the boulevards, and in a few months all the inhabitants re-
siding between the "New Opera" and the Passage Jouffroy will
thus be enabled to benefit from the immense advantages ottered
by this new light over the old gas.

Already oxyhydric lanterns have been placed at the entrance of
the bazaar European, near the Passage Jouffroy, and project a
light of the purest white and the most dazzling brilliancy, near
which the old gas pales and appears to shine with the most singu-
lar yellow color.

The journal referred to congratulates M. le Prefet de la Seine
for having ratified a measure in accordance with the general
wishes and interests of the people, and which appears to it to be
the indispensable corollary of the great improvements under-
taken within a few years in Paris.

USE OF CALCIUM LIGHTS AT THE ST. LOUIS BRIDGE.

Mr. W. Milnor Roberts, who is in charge of the work, says :
" We have used calcium lights only for our open-air work in lay-
ing masonry on the top of our caissons, one light on one side,
and one at the other, on diagonal corners ; we found that thev

c * /

distributed the best light when thus placed. We had the oxygen
gas forced into copper gas-holders with a pressure of about 200
pounds to the square inch. These were carried over from the
city to the piers on a little steamer, and the gas was conveyed to
the burner through small lead pipe. At first our reflectors were
of glass, but so many were broken that they were replaced by
metal. A man remained with the two burners through the night,
to regulate them occasionally, and to mend the pipes when a
burst occurred. They usually burn from 11 to 12 hours; and,
with the aid of some movable large reflector lamps, the masons

104 ANNUAL OF SCIENTIFIC DISCOVERY.

worked as well at night as in the day. The cost of the calcium
lights to our company was 3| dollars per hour each."

MACHINES FOR PREPARING RHEA GRASS.

A short time since there appeared in our columns an advertise-
ment from the Government of India offering a reward of 5,000
for the production of the best machine for the extraction of fibres
from the Hhea grass and preparing it for market. The condi-
tions upon which this prize was offered will doubtless be remem-
bered by all interested in the subject, and we need not, therefore,
refer to them again on the present occasion. The great draw-
back which has hitherto prevented the utilization of this grass has
undoubtedly been the difficulty of extracting the fibre, the manual
process being so expensive as almost to amount to a prohibition,
of fibre manufacture being carried on. "Engineering" states
that during the last 20 years or so, a number of machines
have been brought out for extracting fibre, but none of
these have been considered entirely satisfactory. Up to the
present time the common mode of extracting the fibre from such
plants as the aloe is by soaking the leaves in water till the vas-
cular matter has become rotten, and then beating off this decayed
matter from the fibre with a wooden mallet, or scraping it off
with a blunt knife. This process is not only a slow and nasty one,
but is attended with much w r aste of fibre ; it also discolors, and,
what is most important of all, weakens the fibre. At the London
Exhibition of 1862, two American gentlemen named Sanford and
Mallory exhibited a machine for extracting fibre from aloe, plan-
tain, or pine-apple leaves. This machine has been used in
America, but would scarcely be found either sufficiently simple
or cheap for the ryots of India, its cost being about 45. What
is wanted is a cheap machine of simple construction, by which
the fibre can be easily extracted ; and we think it only due to
those of our readers who have contemplated entering the com-
petitive list for the above-mentioned prize to state that a machine,
possessing, so far as our present information goes, all the neces-
sary requirements, has already been invented in India by Mr. Don-
ald Cruikshank, representative of the Telegraph Construction and
Maintenance Company. No preparation of the leaves is required
for this machine ; they are taken to it green, just as they are cut
from the bushes, and in the wonderfully short space of 2 minutes
the fibre in the leaves is brought out stripped of vascular matter,
and in admirable condition. The rotting process not being nec-
essary with this machine, the deteriorations in color as well as
in the strength and fineness of the fibre, which follow upon the
adoption of that process, are avoided. A correspondent of an
Indian contemporary asserts that the samples from Mr. Cruik-
shank's machine were " fine, delicate, and even ; not one was cut
or broken ; and the material would readily fetch 50 a ton in the
home market." Assuming that the efficiency and simplicity of
the machine is equal to anything that is likely to be set up in com-

MECHANICS AND USEFUL ARTS. 105

petition with it for the offered prize, we very much doubt whether
it is likely to be surpassed in point of cheapness. It is so easily
worked, AVC are informed, that any native may be taught to use
it in an hour's time, and its construction is so simple that it can be
sold at 10 rupees (1 sterling). Scientific Annual.

NICKEL PLATING.

The specimens of nickel plating are exceedingly interesting.
It is only recently that attention has been called to this new in-
dustry, but the success that has attended its introduction is most
gratifying. If, as is claimed by the company, nickel can be de-
posited so much cheaper than silver, we see no reason why it
should not be generally adopted. As it does not oxidize or rust,
or become tarnished by fumes of sulphur, and is hard and will
wear for a long time, it will find favor even if the cost were the
same as that of silver. The company claim that " the cost of
nickel plating is from 20 to 30 per cent, cheaper than silver,
presents a more stable and uniform brilliancy, and lasts 4 times
as long as silver plating of like thickness. We should suppose
that nickelizing would be advantageously employed as a substi-
tute for galvanizing for metals used on board ships ; it can also be
used to advantage on guns, harness, carriage-trimmings, surgical
and philosophical instruments, reflectors, knives, forks, machin-
ery of all kinds, and all models that require to be protected from
the oxidizing or corroding action of the air or water. As nickel
is a magnetic metal it cannot be used about the ship's compass ;
but on the state-room doors and ornamental hinges and knobs it
can have no bad effect.

The following is the substance of the patent granted to Dr.
Isaac Adams, March 22, 1870. The process is said to be very
successful :

This improvement consists in the use of 3 new solutions from
which to deposit nickel, by the electric current: First, a solution
formed of the double sulphate of nickel and alumina, or the sul-
phate of nickel dissolved in a solution of soda, potash, or am-
monia-alum, the 3 different varieties of commercial alum; second,
a solution formed of the double sulphate of nickel and potash ;
third, a solution formed of the double sulphate of nickel and
magnesia, with or without an excess of ammonia.

I have found that a good coating of nickel can be deposited by
the battery process from the solutions hereinbefore mentioned,
provided they are prepared and used in such a manner as to be
free from any acid or alkaline reaction.

When these solutions are used, great care must be taken, lest
by the use of too high battery power, or from the introduction of
some foreign matters, the solution becomes acid or alkaline. I
prefer to use these solutions at a temperature about 100 Fah.,
but do not limit my invention to the use of these solutions at that
temperature. I therefore claim 1. The electro-deposition of
nickel by means of a solution of the double sulphate of nickel

106 ANNUAL OF SCIENTIFIC DISCOVERY.

and alumina, prepared and used in such a manner as to be free
from the presence of ammonia, potash, soda, lime, or nitric acid,
or from any acid or alkaline reaction. 2. The electro-deposition
of nickel by means of a solution of the double sulphate of nickel
and potash, prepared and used in such a manner as to be free
from the presence of ammonia, soda, alumina, lime, or nitric
acid, or from any acid or alkaline reaction. 3. The electro-
deposition of nickel by means of a solution of the double sul-
phate of nickel and magnesia, prepared and used in such a man-
ner as to be free from the presence of potash, soda, alumina, lime,
or nitric acid, or from any acid or alkaline reaction.

USE OF BORAX IN GLASS MANUFACTURE.

|

MM. Maes & Clemendot, glass manufacturers at Clichy, pro-
duce a crystal as fine as the best Baccarat and St. Louis crystal
by using boracic acid.

The presence of this flux allows a modification in the composi-
tion of the crystal, as the oxide of zinc can then be substituted
for the oxide of lead ; and soda, lime, or barytes can thus replace
potassa.

The barosilicates of zinc and potassa, of potassa and barytes,
of soda and zinc, manufactured by Maes & Clemendot, are re-
markable for their limpidity and whiteness. The following are
the proportions :

Silicious sand (white), 261 225

Minium, 2G1 225

Potassa^lst quality), 60 52

Borax, 18 4

Nitro, 18 3

Manganese, 18 1

Arsonious acid, 18 1

Refuse of former operations, 18 89

GLYCERINE CEMENT.'

Professor Hirzel, of Leipzig, has discovered an important use
of glycerine that ouo'ht to be more generally known. He finds

^J \J Vj -

that when glycerine is mixed with fine and well-dried litharge,
it yields a cement that is capable of a large number of applica-
tions.

All metals and nearly all solid bodies can be bound together by
this cement ; it is said to harden underwater as readily as in the air,
and to resist a temperature of 500. It is especially recom-
mended for such pieces of apparatus as are exposed to the action
of chlorine, -- hydrochloric acid, sulphuric acid, sulphurous acid,
and nitric acid ; also the vapor of alcohol, ether, and bisulphide
of carbon, as none of these agents act upon it. The cement can
be used in steam engines, pumps, foundations for machinery,
and, finally, as a substitute for plaster in galvano-plastic and

MECHANICS AND USEFUL ARTS. 107

electro-plating. The proportion of glycerine and litharge to be
taken must depend somewhat upon the consistency of the cement,
and its proposed uses. An excess of glycerine would retard the
setting, as it does not readily evaporate. This new use of glycer-
ine adds another application to a substance that only a few years
ago was thrown away.

CHINESE GOLD-LACKER.

The gold-lacker lining of a Chinese cabinet in the Museum at
Cassel peeled off, and thus gave Dr. Wiederhold the opportunity
of studying the composition of this substance. On examining it
lie found particles of tin foil attached to the lacker; so he comes
to the conclusion that this material formed the ground upon
which the lacker varnish was laid. His attempts to imitate the
varnish were perfectly successful, and he gives the following
directions for the preparation of a composition which closely
resembles the true Chinese article. First of all, 2 parts of copal
and 1 of shellac are to be melted together to form a perfectly
fluid mixture, then 2 parts of good boiled oil, made hot, are to be
added ; the vessel is then to be removed from the fire, and 10
parts of oil of turpentine are to be gradually added. To give
color, the addition is made of solution in turpentine of gum gutta
for yellow, and dragon's blood for red. These are to be mixed
in sufficient quantity to give the shade desired.

MALLEABLE PROPERTIES OF CHINESE BRONZE.

The "Journal of Applied Chemistry" thinks the unsuccessful
attempts made to manufacture Chinese gongs and bells, in Europe
and tlie United States, are due to the mistake that was made of
hammering the Chinese alloy at the ordinary temperature, instead
of working it at a high temperature, according to the recent dis-
covery made by Professor Riche, of Sorbonne, Avho has been per-
fectly successful in his experiments made on a large scale at the
Paris Mint.

The different analyses have shown that the Chinese alloy was
formed of a certain proportion of tin and copper, in the propor-
tion of 20 parts of tin to 80 of copper. Ingots of bronze were cast
containing 21.5, 20.0, 18.5 per 100 of tin; these were afterward
submitted to the action of the hammer, at temperatures varying
from the ordinary temperature to a red heat. At the ordinary
temperature the metal was as brittle as glass, but approaching
300 to 350 Centigrade a sensible amelioration was noticed. At
a dark-red heat it appears that the condition of the metal is quite
different, as this alloy can be worked as easily as iron or bronze of
aluminium.

The metal flattened without cracking under the most powerful
blows of enormous hammers, and can be reduced without the
slightest difficulty to sheets of one millimetre thickness. These
sheets have exactly the appearance of the Chinese bronze, and pos-
sess great flexibility.

108 ANNUAL OF SCIENTIFIC DISCOVERY.

The action of the laminating is more striking, because, under
the hammer, the metal is so soon cooled ; that is, it has to be re-
heated from time to time, "which operation complicates the work ;
in using a laminating machine the work is done with extreme
rapidity, especially if care is taken to heat the alloy to a red heat.
At an ordinary temperature a single passage under the lamina-
tors would break the sheet in thousands of pieces. This alloy can
be cut at a high temperature like iron and steel, and presents the
fine and homogeneous grain of the latter; it is soldered without
difficulty with^he ordinary jewellers' solder.

The following tests will demonstrate that the density of the
bronze suffers very little modification by the hammering or lami-
nating process :

Chinese Bronze. Density nftcr Smelting. Density after Hammering.

Bronze at 21.5 per cent, tin, 8.938 8.929

Bronze at 18.5 per cent, tin, 8.882 8.938

Bronze at 20.0 per cent, tin, 8.924 }

Bronzo at 20.0 per cent, tin, 8.918 > 8.920

Bronze at 20.0 per cent, tin, 8.912 )

ZINC AS A BUILDING MATERIAL.

Stone, and stone only, says the " American Builder," has
always been deemed, by architects and others, the appropriate
material to be employed in the ornamentation of buildings, and
doubtless there has existed, until a comparatively recent date, the
best of reasons for this theory. First, stone is durable ; there is
nothing ordinarily entering into the composition of our buildings
that, in this respect, can compare with it ; and again, from its
peculiar facilities, few other suitable substances can be worked
into the required form, offering the means for such boldness and
strength in the general effect, or such correctness and delicacy of
detail. On the other hand, however, stone can be employed only
at a considerable expense, both in working and transportation,
and, in some localities, distant from quarries, this expense reaches
a point where the employment of such material is practically pre-
cluded, save where its use is an absolute necessity. In orna-
mented fronts especially, where stone has heretofore been con-
sidered indispensable, its use is being discarded, and metal
imitations are taking its place.

The principal objections raised against the use of metal lie in
the fact that it is untruthful, and, therefore, inappropriate ; but
certainly the use of an imitation in this particular is in no sense
more appropriate than the use of hollow iron columns in imita-
tion of stone, and the employment of similar counterfeits in in-
terior ornamentation. Prominent" among the substitutes for stone
is zinc, a material which has proved eminently adapted to the
purpose, and is rapidly acquiring a place among the building
material from its adaptability to all forms as well as from its last-
ing qualities. With the introduction of pressed ornaments of
tliis material the expense of exterior decorations has been greatly

MECHANICS AND USEFUL ARTS. 109

reduced, and an additional advantage is gained in the fact that,
from the facility with which it is worked, there exists but little
difference in the cost of the plainest and most elaborate patterns.
The work, when coated with paint suited to the purpose, may be
made to resemble cut stone work so closely as to deceive the eye
of any one not an expert ; and in like manner the interior of
buildings can be ornamented with zinc in imitation of stucco, or
embellished with elaborate mouldings at a small cost, which work
may be cleaned at any time without fear of injury. In the orna-
mentation of old buildings, which, if of cut stone, could only be
accomplished by taking down the walls, zinc also plays a useful
part, as decorations may be put on without displacing any portion
of the structure. As a roofing material its value has become
generally acknowledged in Europe, and, in this country, is
rapidly acquiring an equally high reputation, particularly in the
construction of large buildings. When exposed to the influence
of the atmosphere, the oxidation that at once ensues, instead of
rapidly eating up the metal, soon forms a crust which hardens
and effectually protects the body of the covering from further
damage.

The points which we have presented above in regard to orna-
mentation are simply those which seem most important in demon-
strating the value of zinc as a building material, and while we
do not by any means advocate its use generally in the place of
stone in ornamentation, where stone is plenty and cheap, yet we
wish, if possible, to overcome the prejudice which appears to
exist in many instances where the employment of zinc would be
more economical and equally appropriate.

PROGRESS OF INVENTION ABROAD.

Iii a paper read before the British Association for the Ad-
vancement of Science, Mr. J. W. Cooper, who has given much
attention to the Watering of Streets by Chemicals, states that 3 streets
in the city of Liverpool were watered with salts during the
month of July, 1869, with very favorable results, so much so
that the experiments were continued this year. It was difficult
to prove the economy resulting from the use of chloride over a
limited area ; and the Westminster Board of Works, after observ-
ing the effect produced at Whitehall and Knightsbridge, resolved
to extend the experiment throughout their entire district, com-
prising an area of 250,000 square yards. As soon as the area was
extended, the economy in labor and water was at once made
evident. By using 1| ton of chlorides per day, costing 3 15s.,
the labor of 10 cart-horses and men, costing 4 10s. (at 9s. per
horse, cart, and man), can be dispensed with, and, consequently,
the quantity of water they would spread is saved also, namely,
350 loads of 250 gallons each, which, at lOd. per 1,000 gallons
(a fair average price for water in London) , would amount to 3
12s. lid. in addition to the 15s. per day saved in labor; thus
showing a clear gain of 4 7s. lid., after paying for the salts.

110 ANNUAL OF SCIENTIFIC DISCOVERY.

An effective method of remedying the evils arising from organic
matter deposited on public thoroughfares is becoming daily a
serious matter for consideration with sanitary authorities, as much
sickness is believed to arise from the malaria emanating from
this source. The disgusting odor and dangerous nature of some
of the deodorizing agents used were strong evidence that they
would not be used at all if the necessity for some determined
action to prevent the spread of contagion and disease was not
fully recognized. The deliquescent chloride of aluminum, re-
cently introduced to public notice by Professor Gamgee, seemed
to meet all the requirements needed in the antiseptic of the
future. It was non-poisonous, and free from any odor; it pre-
vented decomposition, and arrested it when commenced. It
absorbed noxious gases resulting from putrefaction, and de-
stroyed parasites and germs. It was also not to be surpassed as a
precipitant and deodorizer of sewage, and was only one-third the
cost of carbolic acid. Mr. Cooper proposed to add a sufficient
percentage of this chloride to the salts for street-watering, and
thereby afford a means of thoroughly and effectually purifying
public thoroughfares without additional cost to the rate-payers,
the value of the water and labor saved being more than sufficient
to pay for the use of the chlorides.

There seems to be considerable activity in invention abroad.
The stimulating . effect of the war on military invention seems,
however, to be gradually subsiding.

Interesting to nautical men is a newly patented Steering Gear,
which is an ingenious application of hydraulic pressure to move
the rudder. The rudder-head is provided with a strong tiller,
which is actuated by means of a pair of hydraulic rams placed
horizontally on each side of the tiller athwart the ship. These
rams are connected together at their inner ends, between which
they carry a block or bush, which works on the turned cylindri-
cal end of the tiller, and which permits the tiller to slide radially.
These hydraulic cylinders have branches attached to their outer
ends, to which strong hydraulic pipes terminate in a slide valve
chest having three ports, namely, one of the end ports, commu-
nicating with one of the above-named hydraulic cylinders, which
the inventor calls the port cylinder, the other extreme part with
the other or starboard cylinder, and between these two ports the
exhaust port is laid.

Mr. E. Weare, of Stonehouse, England, has patented a method
of Utilizing Waste Thread in the manufacture of textile fabrics. lie
accomplishes the end sought by returning the waste threads to
the condensing carding engines by means of mechanism, the
greater part of which is attached to one of the scribblers, in pref-
erence to the last. Over the end of the carding engine, rollers
are fixed, over which rollers the waste thread from one side of
the engine is conducted to the other side, and the threads from the
two sides of the engine thus brought side by side. The waste
threads are taken up by, or coiled upon, a roller or spoon driven
by any convenient gearing from the carding engine or otherwise ;
and the said roller or spool, when filled with the waste threads,

MECHANICS AND USEFUL ARTS. Ill

is conveyed to the scribbler (the axis of the roller or spool placed
in suitable supports), and made to bear or rest on a second roller
or drum, which ha,s a slow, uniform rotary motion communicated
to it, whereby the waste threads are uniformly delivered into the
sliver as it comes off the scribbler. The sliver passes to the con-
densing carding engine in the usual way.

Pentagrapliic Embroidery is a name applied to an ingenious
method of performing needle-work, invented by Mr. Billwiller, of
St. Gall, England. A number of jointed frames are employed, each
carrying tambouring or sewing apparatus. They are so arranged
and connected together that the needles they carry may be made
to traverse in any direction over the surfaces of the fabrics to be
embroidered, and that the movements of the several needles shall
be simultaneous and similar. The needle-frames are also con-
nected with apentagraph having a tracing point capable of being;
led by the workman over the lines of a pattern which it is desired
to cop} 7 , and when this is done the needles will each travel in and
work along a path similar to that passed over by the tracing point.
Thus each needle will produce embroidery resembling the pattern,
but not necessarily of the same size ; usually it is preferred that
the pattern should be on a larger scale than the work produced
by its means.

Paving Streets French consists, first, in the employment
of wood disintegrated into fragments, of as great a length as
possible, in the construction of rides and bridle-paths, carriage-
drives, riding-schools, and training-grounds, streets and roads of
all kinds. Second, in the employment of disintegrated wood of
shorter length than the preceding, in the construction of foot-
paths of all kinds for promenades and gardens. Third, in the
employment of disintegrated wood, mixed or not with pitch or
with antiseptic material, or both, as a cushion for supporting the
sleepers of railways. Fourth, in the employment of this disinte-
grated wood, mixed with pitch obtained from gas tar or otherwise,
or with natural asphalte or bitumen in the construction of roads,
footways of streets, public drives, and any description of works
in which asphalte is ordinarily emplo}"ed.

Sir William Fairbairn, of Manchester, England, has invented
an improvement in Steam Boilers in which he combines together
3 cylindrical shells of boiler plate. He arranges them parallel
the one to the other, and horizontally, or nearly so. Two of the
cylinders, which are set side by side, are each traversed from end
to end by an internal tube, in which are the furnaces, and these
cylinders each communicate with the third cylinder, which is
placed over and between them, by 3 or other number of pipes or
passages, of sufficient size to allow the steam -generated in the
lower cylinders to escape freely into the upper, and to allow the
water freely to circulate.

A Liverpool inventor has patented a taper or Friction Light,
which is made after the following formula: He takes 1 ounce

^j

saltpetre, one-half ounce powdered orris-root, one-eighth ounce
of minium, and 1 ounce of phosphorus, or any other convenient
friction-match composition. To these ingredients, the phospho-

112 ANNUAL OF SCIENTIFIC DISCOVERY.

rus being dissolved, he adds 1 to 2 ounces of oil, preferably castor,
oil, varying the quantity according to the nature of the oil and the
resultant tenacity or flexibility required. After all the ingredi-
ents are well incorporated, the inventor adds thereto chloride of
sulphur, in the proportion of from 10 to 15 parts of liquid chlo-
ride of sulphur to every hundred parts of oil, agitates quickly,
and shapes into the form required, either by moulding, cutting,
pressing, or drawing.

A very ingenious automatic device for Flushing Seivers has been
produced by a London inventor. In this device, the flood-gate
is hinged, opening upward and outward upon the release of a
hook bolt by the buoyant power of a large copper float. Many
lives have been lost through the action of poisonous gases, in
flushing sewers, which flushing this simple device does whenever
it is required. The rush of accumulated water swings the gate
outward, and also carries off accumulations of sewage. As
soon as the flood current subsides, the gate swings back to its
original position, and is automatically locked.

A machine for Hackling Long Vegetable fibres, such as aloe,
manilla, hemp, etc. s consists of a drum, revolving on a horizontal
axis, and armed with teeth or spikes pointed at the end, and
having sharp, annular edges in front, or at the front and back.
This drum is of such a size that the fibre upon the machine shall
not be able to lap more than about half way round it. This is
an English invention.

A French invention, in the same line as the above, is a machine
for Combing Flax. Two endless chains, consisting of flat links,
are caused to travel together over flat-sided pulleys, and disposed
one above the other; the two adjoining or opposing suri'aces of
the two chains being held in contact with each other by passing
between guides. These surfaces form nippers for holding the tufts
of fibres while being combed or straightened, and serve to carry
them along, at the same time, to a receiving-trough, wherein
each tuft is deposited in succession, the one overlapping slightly
the other. The bottom of the receiving-trough conststs of an
endless travelling band, which continuously conveys away the
combed tufts in the form of a ribbon or sliver. A vibrating arm,
worked by a crank and provided with a cross-head or rake, serves
to take each tuft as it is released from the nippers, and draw it
into the receiving-trough.

A Swedish inventor has patented a process for making Artifi-
cial Leather. He takes leather wastes, leather cuttings, leather
shavings, or other small bits of leather, either new or old, and
reduces them to a kind of fibrous pulp, by hand labor, or by a
machine or mill (either by grinding, pounding, cutting, rasping,
carding, or grating) ; if old waste is used it should first be cleaned
thoroughly. This matter or pulp is then kneaded with India-
rubber, which is rendered fluid, or dissolved in oils or spirits, and
treated with ammonia. He prefers to dissolve the India-rubber
in oil of turpentine. To effect this, the inventor cuts the India-
rubber into pieces and mixes it with the oil, after which he
lets it remain quiet in a closed vessel until it is dissolved. When the

MECHANICS AND USEFUL ARTS. 113

India-rubber is dissolved, he adds ammonia, of a strength of 30
per cent., in the proportion of about equal parts by weight of
ammonia to the India-rubber contained in the solution ; when the
mass has become of a grayish-white color it is ready to be mixed
with the pulp.

A protective coating for iron and other metals has been in-
vented by Mr. J. Crouziers, of Ollioules, France, to which the
inventor has given the name of Electro-Catlwdic Insulating Mastic,
which to the scientific reader will convey the fact that its
application will prevent the corrosion of metal when immersed
in fluids calculated to generate galvanic action. Its composition
and application are as follows : Take of sulphur (say) 38 per
cent. ; coal tar, 20 per cent. ; gutta-percha, 5 per cent. ; minium,
or red lead, 6 per cent. ; white lead, 7 per cent. ; pitch, 10 per
cent. ; resin, 10 per cent. ; spirit of turpentine, 4 per cent. ; total,
100. Melt the sulphur in one vessel, and coal tar, gutta-percha,
minium, white lead, pitch, and resin, all together, in another;
but before adding the gutta-percha to the coal tar, dissolve it, as
far as possible, in the spirit of turpentine, and when all these
ingredients have melted, pour in the sulphur very gently from the
separate vessel, then thoroughly mix the whole, and apply the
composition hot by the aid of a brush, by dipping the article to be
coated into it, or in any convenient manner.

Mr. Crockford, of Dublin, Ireland, has invented several new
processes for utilization of waste products. One of these is a
method of treating what is known as flux skimmings, produced
in the process of galvanizing or coating iron with zinc. For this
purpose he adds a sufficient quantity of hydrochloric or sulphuric
acid to the flux skimmings to dissolve all the zinc, and then pre-
cipitates all the zinc with the ammoniacal gas arising from the
distillation of gas liquor, by which means he obtains oxide and
sulphide of zinc and hydrochlorate or sulphate of ammonia.
Sometimes he passes through the solution, toward the end of the
operation, a stream of sulphuretted hydrogen, for the purpose of
rendering the precipitation quite complete.

A second process by the same inventor consists in the treat-
ment of the liquor from paper mills resulting from boiling esparto
grass, wood, or other materials in caustic soda. He first evapo-
rates the liquor to diyness, and then submits the dry product to
distillation at a red heat, whereby the volatile and other matters
are collected, and he afterwards extracts the carbonate of soda
left in the furnace or retort in which the distillation has been
effected by lixiviation, at the same time extracting a quantity of
black, similar to " lamp-black."

The same inventor has devised a method of condensing and
collecting the fumes and gases from the flues of furnaces in which'
lead and other ores are smelted. To do this he draws off the
mixed fames and gases from the flues of furnaces wherein lead
or other metal is smelted, and forces them, by means of a fan or
other similar means, into and through a quantity of filtering
material, such as canvas, cotton, or fine coke, which material
may be renewed from time to time whe-u it becomes clogged : be-

114 ANNUAL OF SCIENTIFIC DISCOVERY.

fore passing the fumes and gases through the said material they
are cooled by passing them through showers of water or otherwise.
Thus materials which would otherwise be destroyed by the heat
are utilized.

A Hungarian gentleman has, we are told, constructed a rail-
way 5 miles in length on a mountain in the heart of Hungary.
A remarkable peculiarity is the total absence of all permanent
way. Square beams of oak 8 in. high and 14 in. broad are laid
on the ground, and only at rare intervals, where the great un-
evenness of the ground absolutely requires it, cross-sleepers are
laid under them. Each of these longitudinal beams has a length
of 18 ft., and on the two edges of the beams are the rails, which
are only 2 in. broad, and so thin that they weigh about 1 Ib. per
foot. These beams and rails may be taken up at any moment,
and the railway thus relaid whenever it is required. The trucks
run on two pairs of wheels 8 in. in diameter; the bodies of the
trucks are about 3 times the width of the rails, and are placed
so low on the wheels that they have just room to pass over them.
The arrangement of the weight and the system of brakes are
said to be so perfect that the" train may be stopped when on a
gradient of 1 in 7, And going at the rate of 20 or 30 miles an
hour, within 6 to 8 yards. The o miles cost 10,000 dollars,
and after the experience now gained the work may be done for
about 1,000 dollars per mile.

The substitution of heavy paraffine oils for high-pressure steam,
used to obtain high temperatures for the evaporation of liquids,
has been made in an establishment at Lambeth, England. These
oils may be heated safely to a temperature of from 600 to 700
Fah., and they circulate in heating exactly like water. In the
establishment alluded to the apparatus used is as follows : A close
system being made, the oil heated in a coil pipe placed in a fur-
nace rises first to an air-tight tank, from which it runs through
pipes and the jackets of pans, descending as it cools to the coil of
pipe in the furnace. It is claimed that the method, besides being
safer, is more economical than steam. A pyrometer is contrived
to show the exact temperature of the oil as it leaves the tank, and
means are provided for regulating and keeping the temperature
uniform. This method appears to us to possess great promise,
and, if it prove entirely successful, is capable of extension to
many important branches of industry.

Al. Ducomet, of Paris, has invented a simple and ingenious
method of cutting glass tubes. It consists in the employment of
a metallic rod with a diamond set in one end, the rod being cov-
ered with plaited cotton and supplied with a movable gauge to
regulate the length. To use this instrument, all that is neces-
sary is to introduce the end carrying the diamond into the
tube to be cut, and then turn it around so as to make a
scratch with the diamond around the interior of the tube
at the point where it is desired to separate the latter. The
correct position of the cut can be insured by the use of the
guard, which can be lixed at any desired point on the rod by a
screw. After the cut or scratch has been made in the manner

MECHANICS AND USEFUL ARTS. 115

described, the tube can be at once divided at the desired point by
merely bending it, or, if the piece to be cut off is very short, all
that is necessary is to hold the tube above the flanie of a lamp or
candle, when it will at once divide at the point where the diamond
cut was made. M. Ducomet states that it is absolutely necessary
that the rod should be covered with cotton or similar soft material,
or that otherwise tubes cut in this way gauge-tubes for instance
will subsequently break when in use. The instrument is par-
ticularly adapted to cutting gauge-tubes.

SINGLE RAIL TRAMWAY.

Mr. J. W. Addis, C.E., is experimenting in India on a new
form of single rail tramway. The vehicles used, in addition to
the ordinary wheels, have a pair of flanged wheels, one behind
the other, running on the single rail, which is laid at the centre
of the track. The flanged wheels are adjusted by a screw so as
to take all the weight off the ordinary wheels, without lifting
them much above the roadway. An experimental line has been
laid, in part at an incline of 1 in 40, and along this a pair of
bullocks draw a load of 3 tons. The advantages claimed for the
system are : first, a very great diminution of power expended
in hauling as compared with traction on common roads ; sec-
ondly, that the cost of construction is only one-half that of an
ordinary tramway with 2 lines of rails. A tramway or railway
on a similar principle was, we believe, tried some time ago in
France. Science Ileview, Oct., 1870.

<

VENTILATION OF COAL MINES.

Mechanical ventilation in coal mines is steadily gaining
ground on the older plan of producing a draught in the up-cast
shaft by means of a furnace. Mr. D. P. Morrison recently read
a paper on the subject before the North England Institute of
Mining Engineers, at which he stated, that in the deepest Eng-
lish coal mines, mechanical ventilation would show an economy
of 35 to 40 per cent, over furnace ventilation. After discussing
various arrangements of mechanical ventilators, he gave the pref-
erence to the Guibal centrifugal fan. Science .Review, Oct., 1870.

PETROLEUM FOR HEATING LOCOMOTIVE BOILERS.

Two engines on the Strasbourg line have been fitted with M.

^j tj

Deville\s furnaces, and are employed in the goods traffic. The
consumption of oil in the engines drawing heavy trains is stated
to have been from 3 to 5 kilogrammes for every kilometre trav-
ersed, or from 8 pounds to 12 pounds for every two-thirds of a
mile. The oil is said to be very completely burned, and there is
no smoke and consequently no waste. Another advantage
claimed is, there being no sulphur in the oils the atmosphere of

116 ANNUAL OF SCIENTIFIC DISCOVERY.

the tunnels would be free from that most disagreeable and obnox-
ious contamination, sulphurous acid. Journal Franklin Insti-
tute.

*

SLAG.

Mr. Joseph Woodward has taken out a patent, which may turn
out to be of great importance to every iron-smelting district in
England. The millions of tons of slag running from the blast
furnaces, and piled up in such unsightly heaps in all such districts,
are to be utilized in the manufacture of a new brick. It is
stated that the brick is damp-proof, that it is very solid and firm,
without Haw, and pleasing to the eye. The inventor opines that
it is likely at once to take the place for ornamentation at present
occupied by the costly Staffordshire blue brick. Mr. Woodward's
brick can, it seems, be produced so economically, that they can be
offered at less per thousand than the ordinary clay and fire-
bricks. Van NostrancVs Eng. Mag.

AN EARTHQUAKE-PROOF CHURCH.

The people of California, since the earthquakes of 1869, have a
great fear of recurring shocks, and, as an indication of this whole-
some alarm and a desire to prevent loss of life, we have intelligence
from San Francisco that the Roman Catholics are building there
an "earthquake-proof church." This edifice St. Patrick's
Church is built on a plan to prevent loss of life in the event of
the shaking down of the walls. The side walls above the base-
ment are only 30 feet high. At this height a roof rises, which,
with the main roof, is supported independently of the walls by 2
rows of pillars inside of them. Both roofs are firmly bound to the
pillars, and the pillars are fastened together by iron cross-beams,
secured with heavy iron bolts, forming a network of great
strength. The theory of the plan of construction is, that, should
the pillars be shaken down, the roof would be launched off out-
side the walls, instead of falling inside, thus giving a chance of
escape from the ruins. In thus falling, the roof would be carried
aside a distance of 80 feet, the length of the pillars. Scientific
Journal.

MONT CENIS TUNNEL.

The state of the \vorks on Mont Cenis Tunnel, Jan. 1, was as
follows : From the south, 20,510 feet had been executed, and from
the north, 14,95o, making a total of 35,46oi feet, and leaving
4,914 feet to be accomplished. Van Nostrand^s Eng. Mag.

[Jan. 1, 1871. News has been received of its completion.
Editor.']

MECHANICS AND USEFUL ARTS. 117

NEW LIGHTHOUSE APPARATUS.

Iii the Lochindaal Lighthouse, in the island of Islay, Argyle-
shire, dioptric prisms of a new form have been introduced. The
light which passes behind the flame has hitherto been sent forward
by two optical agents, so as to mingle with the front light, and thus
to reach the eye of the mariner; but the object is now effected for
part of the upp'er core of rays by means of the new prisms alone,
so that one agent is saved, and the loss of light by absorption and
superficial reflection is prevented.

The prisms act by refraction and total reflection, and consist of
glass of the ordinary index of refraction. By means of the prisms
.and a spherical mirror, the whole of the back light is sent for-
ward.

THE WORKING OF BRONZE.

The secret of the manufacture of Chinese gongs seems to have
been revealed recently by MM. Julien and Champion, who have
found that bronze, which is brittle at the ordinary temperature,
becomes malleable at a dull red heat. Experiments lately made
on this matter at the Paris mint, with the view of determining the

^j

conditions most favorable to working the alloy, found that a
bronze containing 20 per cent, of tin, which at the common tem-
perature is as brittle as glass, may, at a dull red heat, be forged
and beaten out as easily as soft tin.

IRON SHIPS.

Iron for ships is rapidly superseding wood in English ship-
yards. In 1865 there were 806 wooden ships built in England,
in 1869 but 324. In 1868 the tonnage of iron ships built was
235,937, against 66,977 wooden, and 24,121 of composite. Iron
ships are more durable, require less repairs, and stand heavier
storms than those of wood, and it will not be long till the latter
must be entirely superseded.

GUNNERY EXPERIMENTS.

The London " Globe " details some late artillery experiments
which showed that, in spite of all possible care in the arrange-
ment, the exact level of the centre being taken on the target by
means of a theodolite, the shot would strike 10 inches above it.
Theoretically, the shot would fall by gravity, and its centre
should have struck about 2 inches below the level. The probable
explanation is, that the recoil is sensibly felt before the shot has
left the gun, and that the resultant of the forces acting on the gun
and carriage tends to throw the muzzle up ; thus the projectile,
although seemingly fired point blank, really leaves the gun at an
angle. With the 12-pounder breech-loading gun this angle was
found to equal about 30 minutes, while with the 9-pounder muz-

118 ANNUAL OF SCIENTIFIC DISCOVERY.

zle-loading Indian gun it equals about 13 minutes. The difference
is probably due to the projectile taking a longer time to pass
through the core of the breech-loading gun. It may be men-
tioned that when the gun is swung as a pendulum and fired with
its axis horizontal, the shot strikes below the level.

CUTTING UP LARGE IRON SHAFTS.

The Buffalo correspondent of the "New York Tribune"
writes: "It is frequently very difficult to break up great shafts
of cast iron when, necessary to prepare them for the furnace.
Old cannon have, therefore, sold low. Upon some, powder and
nitre-glycerine have been tried in vain. Some have been burst
by ice, others by wedges driven by machinery or long-continued
hard labor into the muzzle. Here they are cut in two by a con-
tinuous stream of molten iron, which wears away the iron as a
stream of hot water would eat into a mass of ice. The gun is
rolled upon a frame in front of and level with the furnace mouth.
Then the muzzle end is shoved in as far as possible among other
iron, the opening filled up and luted around the gun, the end of
which is melted off. At the next charge it is shoved in another
length, and is thus reduced until the breech can finally be rolled
in and thus finished without any more expense than with pig or
scrap iron.

AN EIGHT-TON STEAM HAMMER.

The Landore Steel Works have erected a single-acting steam
"hammer, the head of which weighs 8 tons. The cylinder is 30
inches in diameter. The anvil block, which is cast in one solid
piece, weighs 75 tons.

CORROSION OF IRON WATER PIPES.

Two wrought-iron -pipes, 7 feet in diameter, have been laid on
the aqueduct bridge by which the Croton water is carried over
the Harlem River, and much trouble has been experienced from
their rusting, but on examination it appears that at each joint,
where a lap of some 15 inches is made, no notable amount of
rust is formed on the entire belt under the lap. It was, at first,
supposed that some molecular change, produced by the riveting
(which is double), was the origin of this protection, but this idea
is opposed by the fact that the rivets in other parts show no such
action, and that the protection in the laps is not concentric with
the rivets, but stop abruptly with the edge of the lap. Mr. Graff
also informs us that the plan of painting the pipes, when hot,
with boiled coal tar, has met with uniform success in his experi-
ence, and also at Boston, where very serious difficulty was before
experienced by stoppage from accumulation of rust. An attempt
to protect the Croton pipes by strips of zinc entirely failed.
Journal Franld'ui Institute.

MECHANICS AND USEFUL ARTS. 119

HIGH-PRESSURE CONVERTER.

Mr. Bessemer has patented a method of conducting his pro-
cess under pressure, by means of which sufficient heat is pro-
duced to retain complete fluidity in the steel until it is poured
into moulds. For this purpose he makes the converting vessel
of great strength and as air-tight as possible, and makes the
mouth of it circular instead of oval, and of smaller size than
usual, lining this mouth with a ring of well-burnt fire-clay or a
composition of clay and plumbago. Mr. Bessemer states that
for the conversion of the purer kinds of Swedish charcoal pig
iron and for mottled or white hematite pig iron mixed with gray,
a back pressure in the vessel of from 8 to 15 pounds on the
square inch will give good results, and in but a few cases will a
pressure of 20 pounds per square inch be necessary ; while a
pressure as low as 3 or 4 pounds will be of little practical
advantage, and below 2 pounds per square inch he lays no claim
to a useful effect.

MAGIC-LANTERN PICTURES ON GELATINE BY A NEW METHOD.

At the last meeting of the Franklin Institute, the Resident Sec-
retary, Prof. Morton, exhibited in the lantern some pictures on
gelatine, prepared in a manner devised by Mr. Shepherd Hoi-
man, ti member of the Institute.

For this purpose, a sheet of gelatine, such as is used for tracing
by engravers, was securely fixed over an engraving, and with a
sharp steel point (made by grinding down the end of a small,
round file), the lines of the original traced pretty deeply on the
transparent substance. Lead-pencil or crayon dust was then
lightly rubbed in with the finger, and the picture was at once
ready for use.

A number of such drawings could be easily carried between
the leaves of a book, could each in succession be placed in a
frame or cell made of two plates of glass supported by a frame
of thin card of three edges, and united by paper or muslin pasted
around the same edges. The effect of these drawings in the lan-
tern was excellent, and their ease of production very great.

PAPER FROM OAT-HUSKS.

W. Hay, of Glasgow, Scotland, has just patented the following
process. He first immerses the oat-husks in water, in a tank or
other convenient vessel, in order to float off mustard and other
seeds with which they are generally more or less mixed, and
which, if not separated, materially deteriorate the quality of the
paper. It is of advantage to have the water well stirred, as it
facilitates the separation of the foreign seeds, and allows them to
float to the surface. The oat-husks are then allowed to settle,
and the surface scum and floating seeds are drawn off by an over-
flow pipe at the top of the tank, or skimmed off by a rake or

X20 ANNUAL OF SCIENTIFIC DISCOVERY.

other tool, or otherwise removed, after which the water is drained
from the oat-husks, by a waste-water pipe at the bottom of
the tank, and beneath a perforated false bottom, fitted with a
strainer which retains the oat-husks. The oat-husks may be left
to steep in the water for from 5 to 10 hours after or during the
removal of the scum, as this steeping, by softening them and
helping to loosen the silica from the fibre, facilitates the subse-
quent boiling process. The remainder of the process does not
differ materially from the ordinary one in making paper from
straw.

AN IMPERISHABLE HOT-HOUSE.

From the recently published list of English patents it appears
that Mr. W. P. Ayres has secured "Improvements in the Con-
struction and Arrangement of Horticultural and other Buildings
or Erections or Structures, and in the Means and Appliances for
Heating the same." These consist of roofs formed without
sashes, sash-bars, putty, or paint, or any wood-work outside, and
consequently no painting will at any time be required. Secondly,
Mr. Ayres forms his floors, plant-stages, and side or partition
walls in slabs of cement concrete, strengthened in a peculiar
manner so as to bear any amount of pressure that may be placed
upon them, and yet admit of being perforated for the air to circu-
late through them, panelled to hold water for evaporation, or the
pots to stand in, or perforated and panelled. These slabs, it is
said, can be manufactured of any required strength, and, conse-
quently, are suitable for fire-proof floors, partition walls, tabling,
or shelving for shop, office, or warehouse fittings, or for any
situations where slate or marble slabs have hitherto been used,
with the advantage that they can be manufactured of any size,
and in the place where they are required to be used, left rough
for ordinary use, or be finished plain or in colors with the face of
polished marble. Thirdly, Mr. Ayres introduces a new system
of heating, dispensing with plunging or fermenting material for
bottom heat, and substitutes a system by which a stream of air,
moist or dry, is constantly passing through the centre of the
earth containing the roots of the plant as well as around the sides
of the pot. For glazing, Mr. Ayres uses flat glass of great
strength and quality, jointed with transparent cement ; or he may
use glass turned up at the sides, or any other form of bent glass
that he may find necessary for the purposes of his invention.
The alleged advantages are, economy in first construction, porta-
bility (when desired), and when manufactured in iron, gal-
vanized, a house so imperishable as to wear for a lifetime without
further cost.

NEW INVENTIONS.

Herring, Parrel & Sherman, at the fair of the American Insti-
tute held in New York, exhibited a new style of burglar-proof

MECHANICS AND USEFUL ARTS. 121

safe, rnade of Franklinite, or spiegeleisen, combined with welded
steel and iron. It is cylindrical, and the top is raised to open the
safe or lowered to close it by a very strong vertical screw in the
centre of the cylinder. As the top is raised, the wood-work, con-
taining drawers and pigeon-holes, also is raised, so as to become
accessible. A combination lock fastens the top when closed, so
that it is held in a very secure manner. This safe appears to be a
very difficult thing for burglars to deal with, and we judge will
not often be attempted by that ingenious fraternity. A desk-safe,
also of new style, exhibited by the same firm, is worthy of notice.

An application of electricity to bank locks, exhibited by the
Electro-Bank Lock Company, No. 9 Willoughby Street, Brook-
lyn, is a most ingenious affair. A combination lock is worked
entirely by electro-magnetism, and is placed within the safe on
the back wall, opposite the door. Its wheels are worked by elec-
tro-magnetism, the circuit being controlled entirely by circuit-
breakers placed in an office desk or any other convenient place.
No one can unlock the safe without knowing the combination, and
no key-hole or any other aperture in the walls of the safe exists
whereby powder can be inserted. Burglars could only enter a
safe provided with this lock by actually penetrating the wall.
The lock itself is absolutely exempt from all tampering.

Among minor steam-engineering devices we noticed the Ameri-
can Eagle Steam Gauge, exhibited by the American Eagle Steam
Gauge Co., 190 Market Street, Newark, N. J., belonging to the
type known as mercurial gauges. It consists of a cast-iron cham-
ber fitted to receive a thin corrugated steel diaphragm or disk,
properly tempered, and plated with nickel, to prevent corrosion.
The pressure acts upon the under side of it, the mercury covering
the top side of the same, from which extends an open vertical
glass tube, supported and protected by a metal case, having a
graduated scale of pressure. Any slight movement of the disc
will fill the tube with the mercury to a greater or less degree,
whereby the pressure is correctly indicated. There is a screw by
which the starting-point of the mercury can be readily adjusted,
so that, whatever the temperature of the surrounding atmosphere
may be, the indication of the pressure will be correctly indicated.

A recording pressure-gauge is shown by Charles G. Willing, of
88 John Street, New York, which gave a continuous and exact
record of the pressure, and the time at which the pressure was
sustained, automatically. The principle of recording is the trac-
ing on a rotating disk of a pencil point in the end of the index
hand.

W. H. Place, 8 Attorney Street, New York, exhibited an im-
proved governor and valve, of novel construction, and apparently
of great effectiveness. Mr. Place, the inventor, was formerly
Chief Engineer of the Central American Transit Company. His
invention consists of a vertical cylinder or case, in which are
placed and attached thereto a series of inclined or spiral-formed
ribs, within which revolves (in water or other liquid) a propeller-
wheel, revolving and leading in an opposite direction from said
spiral ribs in said cylinder, making the shaft, by passing through

11

122 ANNUAL OF SCIENTIFIC DISCOVERY.

a series of friction rolls attached to the throttle valve, check or
increase the motion of the engine, the stem of the shaft of the pro-
peller-wheel passing through friction-rolls without packing, caus-
ing instantaneous and sensitive motion to depress or elevate the
throttle-valve. The governor is operated from the main shaft by
means of a belt and pulleys.

A novelty in the display of minor tools is Jones' Patent Joint
and Mitre Planer, a hand-tool whereby a perfect right-angled or
mitre joint may be made, or a piece be planed square or to any
required angle, with ease and accuracy, even by the inexpert.
This is accomplished by an adjustable table, upon which the
piece is laid, and brought up to the cutting-iron of the plane, at
the angle desired. The plane proper runs on ways, and thus has
a perfectly parallel motion. Scientific American.

GREEN GLASS FOR THE DARK ROOM OF PHOTOGRAPHERS.

Mr. Gaffielcl, of Boston, has shown that while chemical rays to
a slight degree will pass through j^ellow glass, they are perfectly
excluded by green and red. This has suggested to photogra-
phers to substitute green glass for thej T ellow in the developing and
fixing room. The yellow light is very trying to the eyes, while
the green light is very agreeable.

Carey Lea recommends the green glass, after an experience in
the preparation of hundreds of plates where it had been substi-
tuted for the yellow panes.

A NEW WINDOW.

The New York "Technologist 1 ' describes a new contrivance for
preventing people looking into a room, while light is not ex-
eluded. It consists of a number of glass rods arranged either
vertically or horizontally, and secured together by appropriate
frames, forming a series of cylindrical lenses which break up the
light and throw it into every part of the room, thus producing a
soft and diffused glow which is very beautiful and pleasant. The
glass rods may be of any color, and by an arrangement of the
colors very beautiful effects can be produced. The contrivance is
the invention of Mr. Deniuth.

NEW DYE.

The "Engineer" states that the new dye known as soluble
garnet seems to be coming more largely into use on the Continent,
and as the colors produced with it are exceedingly brilliant, simi-
lar to those obtained with archil, but much more stable when ex-
posed to light and air, the garnet dye is likely to become a great
favorite. The dye was first prepared by Casthelaz, of Paris, and
is the ammonia salt of isopurpuric acid, which is formed by the
action of a metallic cyanide upon picric acid. It is not prepared

MECHANICS AND USEFUL ARTS. 123

from the pure crystallized, but from an inferior kind of picric
acid, and is probably destined to replace the archil in many cases,
in imparting to wool all shades, from garnet to chestnut-brown.
It may be readily combined with other pigments, so that a num-
ber of different colors may be obtained. According to Casthelaz,
the dyeing of wool and of silk is effected by the addition of an or-
ganic acid to the bath, for instance, acetic or tartaric acid, min-
eral acids being excluded. The dye-bath for silk should be cold
or tepid in the beginning. Different shades in red and brown are
thus obtained that are dependent upon the concentration of the
bath, the nature of the mordant, and the time of the operation.
Nature.

FIBROUS COTTON-SEED.

Mr. Thomas Rose read a paper at the meeting of the British
Association, "On the Utilization of Fibrous Cotton-Seed.'' He said
that a vegetable production, which should be valuable, and could
be supplied to the extent of millions of tons, was now wasted.
The waste product was fibrous cotton-seed, and in America alone
more than a million and a half tons of the seed were wasted
yearly. The seed was composed of 50 per cent, kernel, which
yielded about one-third oil, and 50 per cent, husk-shell with fibre
adhering, of which the fibre would be one-third. His calcula-
tion was that the waste seeds would produce 250,000 tons of pure
cotton, 250,000 tons of oil, and 500,000 tons of cattle-cake, the
value of which he estimated at 20,000,000 sterling. The husks
could be taken to the paper-mill and the cotton abstracted in such
a manner as to form a most valuable material for paper. There
was a process by which the cotton fibre could be completely sep-
arated from the shell ; and the seed had a chief advantage, that
of unfailing supply. In conclusion, Mr. Rose remarked upon the
value and use of the oil and the cattle-cake that would be yielded
by the seed.

EQUILATERAL TRIANGULAR DRAWING-BOARD FOR ISOMETRICAL

DRAWING.

Mr. George Fawcus, of North Shields, has contrived an equi-
lateral triangular drawing-board for isometrical drawing. An
ordinary T square applied on the edges of an equilateral triangle
draws tangents that meet each other at angles of 120, and other
lines drawn parallel to these radiating ones form with them angles
of GO and 120, which are the exact angles of the apparent
square of isometrical cubes. The inventor "believes that the use
of this new drawing-board will make the teaching of isometrical
drawing both simple and easy. The practice of isometrical
drawing is strongly urged in the science and art drawing classes.
Nature.

124 ANNUAL OF SCIENTIFIC DISCOVERY.

FIXING LEAD-PENCIL, CHARCOAL, AND CHALK DRAWINGS.

TV. Wolanek states, that when the paper containing drawings
or writings made with lead pencil, charcoal, etc., is painted
over on the reverse side (where no writing or drawing exists)
with a moderately strong solution of bleached shellac in alcohol
the same becomes thoroughly fixed, so that they cannot b<j
rubbed off. Journal Franklin Institute.

NOVEL MECHANICAL MOVEMENT.

All exceedingly ingenious substitute, which can be scarcely
called a modification, of the well-known joint of Dr. Hooke, has
been patented within a year, by Mr. Melville Clemens, of Boston,
an illustration and long description of which has been published
in "Engineering," London, September 2, 1870.

Except, to a very careful reader and student, this description is
somewhat appalling (beside involving some errors of statement
and calculation), and the drawings fail to show clearly or readily
the principle on which it is constructed. In fact, the parts lie at
such angles with each other, that neither drawings nor perspective
will convey an adequate idea of the contrivance. It gives the full
range of 90 to the angle at which the shafts (in the same plane
of rotation) may have, and the motion transmitted is a uniform
angular one, ' both of which conditions are advantages not pos-
sessed by the Hooke joint.

If it is imagined that 2 shafts are placed in boxes or pedes-
tals in the same plane, but at any angle with each other from
to 90, the ends of which are tee-headed and placed at such dis-
tance apart that the tee-heads will clear each other (at 90) in
rotating; and if it is further supposed that each tee-head is made
the axis or knuckle of 2 straps or triangular hinges, and the
outer extremities of the hinges are connected (in pairs) with
those which are attached to the opposite tee-head in a ball-joint,
the whole forming a hinged parallelogram, the gist of the con-
struction will be comprehended.

The ball-joint must allow a pestle and mortar motion of 10 to
15 and a rocking motion of 45, and the knuckles on the tee-
heads must rock 90 while the system rotates.

In a practical form for use the joints of this arrangement admit
of as great strength as the Hooke joint, and the extreme range of
angle to which it is applicable will render it available in many
places.

The study of mechanical movements has occupied so many and
so able persons, that the addition of a novel one bespeaks more
than usual ingenuity; and this Clemens joint will at once take a
place in the repertory of general information. Journal Franklin
Institute.

MECHANICS AND USEFUL ARTS. 125

TRANSPORTATION OF FRESH MEATS AND FRUITS, ETC., THROUGH
LONG DISTANCES. THE DAVIS REFRIGERATOR CAR.

The shell of the car consists exteriorly of the ordinary wood
casing. A second wooden shell is made smaller than the first,
and placed within it so as to leave an air space or chamber
entirely around the top, bottom, and sides of the car. Within this
second shell is placed a layer of hair, about 2 inches in thick-
ness, and this again is lined with an interior wooden shell. This
construction makes a non-radiating and non-conducting compound
shell or case, of great power to resist the action of external heat,
and renders the expenditure of ice quite small to maintain the
required depression of temperature, after the interior of the car
and its contents have been cooled clown to the proper point, say
from 34 to 38 Fah.

The refrigeration is accomplished in the following manner :
Along the sides of the car are placed sheet-metal tanks shaped
like the frustra of very gradually tapering wedges. They extend
from the top to the bottom of the car, and are about 5 inches
thick at the top and 2 inches at the bottom. These tanks com-
municate at the top with the exterior of the car through funnel
or hopper-shaped openings, and at the bottom through drip-pipes,
which convey awa}^ the moisture. The funnel-shaped openings
at the top are used for putting in the refrigerating mixture, con-
sisting of broken ice and salt, and are provided with air-tight cov-
ers. The car is entered through a hatchway at the top, through
which its freight is also introduced. This hatchway is also pro-
vided with a tight-fitting cover, made non-radiating and non-con-
ducting, like the sides of the car.

The store of ice and salt for the trip is contained in a separate
department in one end of the car, so that its contents can be
reached, and the refrigerating tanks supplied, without opening the
freight-room.

The freight is placed in the car on strips of board, strips of
board also preventing its coming in contact with the walls of the
refrigerating tanks. The packages are also so placed as to leave
interspaces through, between, and around each. During the
process of refrigeration the air circulates around the packages and
nlong the sides of the tanks like water in a steam-boiler, the colder
air falling, and the warmer air rising to the top, becoming chilled
in its passage along the sides of the tanks, and depositing its
moisture on the tanks till their sides are covered with a thick
stratum of congealed water or hoar-frost. Thus the air is not
only cooled but dried, no accession of moisture being derived
from the external air or from the ice in the tanks, with either of
which the interior of the car has no communication so long as the
car is kept closed.

The two essentials for the preservation of substances liable to
ferment, namely, absence of heat and of moisture, are thus se-
cured in a veiy perfect manner, and the arrangement of the tanks
is such that the space within the car for the storage of freight is
not materiallv reduced. Some addition to the refrigerative mix-

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126 ANNUAL OF SCIENTIFIC DISCOVERY.

tare in the tanks is made each clay, and the temperature is easily
regulated and kept at the desired point by the addition of more or
less salt in proportion to the charge of ice. Scientific American.

PRESERVED FLESH IN AUSTRALIA.

The exportation of this article to England, according to the
newspapers, is assuming great importance, and is becoming with
wool one of the great staples.

The Victoria Company deprives the animal of its bones, skin,
etc., salts it slightly, packs it in casks, filling the interstices
with melted fat. Flesh thus preserved is said to keep excellently.

One company delivers weekly 40 tons of flesh. Condensed from
Polyteclinisches Centralblatt.

PRESERVATION OF MEAT. BY M. GORGES.

The process in use on the large scale by the author, at Mon-
tevideo, is briefly as follows : The meat, in pieces weigh-
ing from 2 to 50 kilos, is placed in a mixture of water (85 per
cent.), the rest being hydrochloric acid, glycerine, and bisul-
phite of soda. After having been steeped for some time, the
pieces are taken out and dusted over with finely powdered dry
bisulphite of soda, and then packed in air-tight boxes, filled
as full as possible. In this state the meat keeps fresh any length
of time, and becomes perfectly fit for use, equal to fresh butcher's
meat, by steeping a short time in water, to which vinegar has
been added, and afterwards exposed to air. The author manu-
factures, at the place above named, an excellent extract of meat,
which can be sold in Europe at 6 francs per kilo. The price of
the preserved meat, of which it would be easy to supply to Lon-
don and Paris daily over 10 tons, is from 50 to 60 centimes per
kilo. Journal Franklin Institute.

NATUKAL PHILOSOPHY.

SIZE OF ATOMS.

SIR WILLIAM THOMPSON, who has been investigating regarding
the probable size of molecules, has derived an important argu-
ment from electrical phenomena. He had previously proved that
" a plate of zinc and a plate of copper, kept in metallic connec-
tion with one another, act electrically upon electrified bodies in
their neighborhood, and upon one another, as they would if they
were of the same metal and kept at a difference of potentials equal
to about three quarters of that produced by a single cell of
Daniell's. Hence, in connection with certain measurements on
the electrostatic effects of that battery, it is found that plates of
zinc and copper held parallel to one another at any distance, D,
apart, which is a small fraction of the linear dimensions of their
opposed surfaces, and kept in metallic communication with one
another, exercise a certain force of attraction which can be calcu-
lated. From this we can calculate the work done if the plates
approach each other from a distance, D', till they arc at this dis-
tance, D. Suppose, now, a pile composed of a great number of
plates of zinc and copper kept in metallic connection while they
are made to approach each other, their positions in the pile being
parallel, and suppose for simplicity that their thickness is also D.
We calculate the work done, estimating it by the height through
which this energy would raise the whole pile, and giving different
values to D we get varying values of this height according as the
energy calculated by the formula varies. Down to values of D
equal to one two hundred-thousandth of a centimetre the values of
the energy computed are such that we may suppose that the laws
of electrical attraction and induction are essentially the same as
have been found for plates of measurable thickness at measurable
distances from each other. But if D equals a very small amount,
as one four-hundred-millionth of a centimetre, the computed
energy is greater than that which converted into heat would melt
the zinc and copper. So we must admit that as zinc and copper
filings have no tendency to inflame on approaching one another,
the electric attraction between plates one four-hundred-millionth
of a centimetre thick, at a distance of one four-hundred-millionth
of a centimetre from each other, must be much less than the
amount calculated, supposing the ordinary laws still to be fol-
lowed ; " or, in other words, plates of zinc and copper, so thin as a
four-hundred-millionth of a centimetre from each other, form a

127

128 ANNUAL OF SCIENTIFIC DISCOVERY.

mixture closely approaching to a molecular combination, if indeed
plates so thin could be made without splitting atoms.

The principles of capillary attraction lead to a similar result.
It has been proved that the dynamic value of the heat required to
prevent a body from cooling when stretched is rather more than
half the work spent in stretching it. Hence, if we calculate the
work required to stretch it to any extent, and multiply the result
by three-halves, we have an estimate, near enough for the present
purpose, of the augmentation of energy experienced by a liquid
film when stretched and kept at a constant temperature. Taking
.08 of a gramme weight per centimetre of breadth as the capillary
tension of a surface of water, and therefore .16 as that of a water
bubble, a quantity of water expanded to a thinness of one two-
hundred-millionth of a centimetre would, if its tension remained
constant, have more energy than the same mass of water in ordi-
nary condition by about 1100 times as much as suffices to warm it
by 1 Centigrade. This is more than enough to drive the liquid
into vapor. Hence, if a film of one two-hundred-millionth of a
centimetre can exist as a liquid at all, it is perfectly certain that it
cannot be many molecules in thickness. The argument from the
Kenetic Theory of gases leads to a similar conclusion, as do other
electrical measurements. The result of the series of experiments
first mentioned gives a certain result for the value (one four-hun-
dred-millionth of a centimetre) there given, and a high probabili-
ty that the limit is at least one two-hundred-millionth of a centi-
metre.

THE CONTINUITY OF THE GASEOUS A.ND LIQUID STATES OF

MATTER.

Among the most important results of physical investigation
recently obtained, are those of Dr. Andrews, on the continuity of
the gaseous and liquid states of matter.

The transition from the gaseous to the liquid state, and from
the liquid to the solid, has been regarded as necessarily abrupt,
with the exception of the plastic condition assumed by some solids
just before liquefaction. Dr. Andrews has shown that this is very
far from being the case.

A series of experiments was undertaken by Dr. Andrews, in
1861, in which oxygen, hydrogen, nitrogen, carbonic oxide and
nitric oxide were submitted to pressures greater than had pre-
viously been obtained in glass tubes, and while under this pres-
sure they were submitted to the cold of the carbonic acid and
ether bath. None of these gases exhibited any appearance of
liquefaction, although reduced to less than one five-hundredth of
their ordinary volume by the combined action of cold and pres-
sure. A short time later a number of experiments were under-
taken with carbonic acid, this being liquefied under certain fixed
conditions of pressure and temperature.

These, together with some later researches, form the subject of
the lecture of which this article is an abstract.

In the earlier experiments Dr. Andrews found that " on par-

NATURAL PHILOSOPHY. 129

tially liquefying carbonic acid by pressure alone, and gradually
raising at the same time the temperature to 88 Fahrenheit, the
surface of demarcation between the liquid and the gas became
fainter, lost its curvature, and at last disappeared. The space
was then occupied by a homogeneous fluid, which exhibited, when
the pressure was suddenly diminished or the temperature slightly
lowered, a peculiar appearance of moving or flickering strife
throughout its entire mass. At temperatures above 88, no ap-
parent liquefaction of carbonic acid or separation into two distinct
forms of matter could be effected, even when a pressure of 300 or
400 atmospheres was employed. Nitrous oxide gave analogous
results. 1 '

In the later series, Dr. A. still made use of carbonic acid. In
his apparatus the carbonic acid was contained in a glass tube,
capillary in the upper and larger part of its length, and for th<;
remainder of the widest bore in which the column of mercury
would remain without displacement when the tube was placed iii
a vertical position. A movable column or bar of mercury con-
fined the gas to be operated on. This glass tube was secured by
careful packing in a massive end-piece of brass, which carried a
flange by means of which a water-tight junction could be made
with a corresponding flange attached to a cold-drawn copper tube
of great strength. To the other end of the copper tube a similar
end-piece was firmly bolted. The latter carried a fine steel screw,
7 inches long, which was packed with such care that the packing
was capable of resisting a pressure of 400 atmospheres or more.
Before commencing the experiment, the body of the apparatus
was filled with water; the upper end-piece, carrying the glass
tube in which was the gas to be operated upon, was firmly secured
in its place, and the pressure was obtained by screwing the steel
screw into the water-chamber. When the gas or liquid was ex-
posed to very low temperatures, the end of the capillary-tube was
made to dip into a bath of ether and solid carbonic acid under a
bell-jar, from which the air could be exhausted.

In order to estimate the pressure in these experiments, a com-
pound form of the apparatus was used, a second tube, containing
air, being put in communication with the first, and used as a
manometer. In order to keep the tubes at fixed temperatures,
each was surrounded with a case, through which a current of
water passed, by which the temperature could be regulated.

The temperature of the water surrounding the air-tube was
kept stationary, coinciding with that of the apartment ; that sur-
rounding the carbonic acid tube was made to vary from 13.1 Cen-
tigrade to 48 Centigrade. .The volumes of both air and gas
were carefully read by a cathetometer.

The observations were recorded by the graphical method, being
embodied in a scries of curves. The air-curves are drawn for
temperatures of 13.1 C., 31.1 C., and 48.1 C., the ordinates rep-
resenting the volumes, and the abscissas the pressures.

In the carbonic acid curves for 13.1 C. there occurs an abrupt
fall (diminution of volume) at a pressure of 49 atmospheres.
The curve for 21.5 C. exhibits a corresponding fall, but not

130 ANNUAL OF SCIENTIFIC DISCOVEKY.

until a pressure of 60 atmospheres is reached. A slight deviation
from perfect abruptness in the fall is shown by Dr. A., to result
from the presence of a small quantity of air in the carbonic acid
tube. The curve for 31.1 C. shows no such abrupt fall, bub a rapid
descent between the pressures of 73 and 75 atmospheres. This
descent becomes gradually less marked as the temperature rises,
and when a temperature of 48.1 C. has been obtained, it has
almost, if not altogether, disappeared.

At any temperature between 57 C., and 30.92 C., carbonic
acid, under the ordinary atmospheric pressure, is unquestionably
in the state of a gas or vapor. On augmenting the pressure,
the volume diminishes at a more rapid rate than that of a perfect
gas, till liquefaction begins, a sudden diminution of volume then
taking place. With some care it is possible to arrange the ex-
periment so that part of the carbonic acid shall be in the liquid,
and part in the gaseous state ; the carbonic acid thus coexisting
in two distinct physical conditions in the same tube and under the
same external pressure. The result is, however, far different if
the experiment be made at 30.92 C. or at any higher tempera-
ture. At this temperature, and under a pressure of about 74 at-
mospheres, the density of liquid and gaseous carbonic acid, as
well as all their other physical peculiarities, are absolutely identi-
cal, and the most careful observation fails to discover any hetero-
geneity at this or higher temperatures in carbonic acid, when its
volume is so reduced as to occupy a space in which at lower tem-
peratures a mixture of gas and liquid would have been formed.
The carbonic acid has, in fact, become one homogeneous fluid,
which cannot by change of pressure be separated into two dis-
tinct conditions. This temperature of 30.92 C., Dr. Andrews
calls the critical point of carbonic acid. Other gases show the
same phenomena, but have different critical points. The rapid
changes in density, which slight changes of temperature or pres-
sure produce, when the gas is reduced at temperatures a little
above the critical point, to the volume at which it might be ex-
pected to liquefy, account for the flickering movements referred
to in the beginning of this article.

" I have frequently exposed carbonic acid," says Dr. Andrews,
"without making precise measurements to much higher pres-
sures than any marked in the tables, and have made it pass,
without break or interruption, from what is regarded by every one
as the gaseous state, to what is in like manner universally re-
garded as the liquid state. Take, for example, a given volume
of carbonic acid gas at 50 C., or at a higher temperature, and ex-
pose it to increasing pressure till. 150 atmospheres have been
reached. In this process the volume will steadily diminish as the
pressure augments, and no sudden diminution of volume without
the application of external pressure will occur at any stage of it.
When the full pressure has been applied, let the temperature be
allowed to fall, till the carbonic acid has reached the ordinary
temperature of the atmosphere. During the whole of this opera-
tion, no breach of continuity has occurred. It begins with a gas,
and by a series of gradual changes, presenting nowhere any

NATURAL PHILOSOPHY. 131

abrupt alteration of volume or sudden evolution of heat, it ends
with a liquid. The closest observation fails to distinguish any-
where indications of a change of condition in the carbonic acid,
or evidence at any part of the process of part of it being in one
physical state, and part in another. That the gas has actually
changed into a liquid would, indeed, never have been suspected
had it not shown itself to be so changed by entering into ebulli-
tion on the removal of the pressure. For convenience, this pro-
cess has been divided into two stages, the compression of the car- '
bonic acid, and its subsequent cooling; but these operations
might have been performed simultaneously, if care were taken
so to arrange the application of the pressure and the rate of cool-
ing that the pressure should not be less than 70 atmospheres
when the carbonic acid had cooled to 31.

"We are now prepared for the consideration of the following
important question : A\ r hatis the condition of carbonic acid when
it passes, at temperatures above 31, from the gaseous state down
to the volume of the liquid, without giving evidence at any point
of the process of liquefaction having occurred ? Does it continue
in the gaseous state, or does it liquefy, or do we have to deal
with a new condition of matter ? If the experiment were made
at 100, or at a higher temperature when all indications of a fall
had disappeared, the probable answer which would be given to
this question is that the gas preserves its gaseous condition during
the compression, and few would hesitate to declare this statement
to be true, if the pressure, as in Natterer's experiments, were applied
to such gases as hydrogen and nitrogen. On the other hand,
when the experiment is made with carbonic acid at temperatures a
little above 31 C., the great fall that occurs at one period of the pro-
cess would lead to the conjecture that liquefaction had actually taken
place, although optical tests, carefully applied, failed at any time
to discover the presence of a liquid in contact with a gas. But
against this view it may be urged with great force, that the fact
of additional pressure being always required for a further dimi-
nution of volume, is opposed to the known laws which hold in the
change of bodies from the gaseous to the liquid state. Besides,
the higher the temperature at which the gas is compressed, the
less the fall becomes, and at last it disappears.

" The answer to the foregoing question, according to what ap-
pears to me to be the true interpretation of the experiments al-
ready described, is to be found in the close and intimate relations
which subsist between the gaseous and liquid states of matter.
The ordinary gaseous and ordinary liquid states are, in short, only
widely separated "forms of the same condition of matter, and may
be made to pass into one another by a series of gradations so
gentle that the passage shall nowhere present any interruption or
breach of continuity. From carbonic acid as a perfect gas to car-
bonic acid as a perfect liquid, the transition, we have seen, may
be accomplished by a continuous process, and the gas and liquid
are only distant stages of a long series of continuous physical
changes. Under certain conditions of temperature and pressure,
carbonic acid finds itself, it is true, in what may be described as

132 ANNUAL UF SCIENTIFIC DISCOVERY.

a state of instability, and suddenly passes with the evolution of
heat, and without the application of additional pressure or change
of temperature, to the volume which by the continuous process
can only be reached through a long and circuitous route. In the

/ d? C_7

abrupt change which here occurs, a marked difference is exhib-
ited, while the process is going on, in the optical and other physi-
cal properties of the carbonic acid which has collapsed into the
smaller volume, and of the carbonic acid not yet altered. There
is no difficulty here, therefore, in distinguishing between the liquid
and the gas. But in other cases the distinction cannot be made ;
and under many of the conditions I have described it would be
vain to attempt to assign carbonic acid to the liquid rather than
the gaseous state. Carbonic acid, at the temperature of 35.5,
and under a pressure of 180 atmospheres, is reduced to 0.480 of
the volume it occupied under a pressure of one atmosphere ; but
if any one ask whether it is now in the gaseous or liquid state,
the question does not, I believe, admit of a positive reply. Car-
bonic acid at 35.5, and under 108 atmospheres of pressure, stands
nearly midway between the gas and the liquid ; and we have no
valid grounds for assigning it to the one form of matter more than
to the other. The same observation would apply with even
greater force to the state in which carbonic acid exists at higher
temperatures and under greater pressures than those just men-
tioned.

" In the foregoing observations I have avoided all reference to
the molecular forces brought into play in these experiments. The
resistance of liquids and gases to external pressure tending to
produce a diminution of volume proves the existence of an inter-
nal force of an expansive or resisting character. On the other
hand, the sudden diminution of volume, without the addition of
external pressure, which occurs when a gas is compressed at any
temperature below the critical point to the volume at which lique-
faction begins, can scarcely be explained without assuming that
a molecular force of great attractive power comes into operation,
and overcomes the resistance to diminution of volume which com-
monly requires the application of external force. When the pas-
sage from the gaseous to the liquid state is effected by the con-
tinuous process described in the foregoing pages, these molecular
forces are so modified as to be unable at any stage of the process
to overcome alone the resistance of the fluid to change of vol-
ume.

" The properties described in this communication as exhibited
by carbonic acid, are not peculiar to it, but are generally true of
all bodies which can be obtained as gases or liquids. Nitrous
oxide, hydrochloric acid, ammonia, sulphuric ether, and sulphuret
of carbon, all exhibited, at fixed pressures and temperatures,
critical points, and rapid changes of volume with flickering move-
ments, when the temperature or pressure was changed in the
neighborhood of those points. The critical points of some of
these bodies were above 100 ; and in order to make the obser-
vations it was necessary to bend the capillary tube before the

NATURAL PHILOSOPHY. 133

commencement of the experiment, and to heat it in a bath of
paraffine or oil of vitriol.

" The distinction between a gas and vapor has hitherto been
founded on principles which are altogether arbitrary. Ether in
the state of gas is called a vapor, while sulphurous acid in the
same state is called a gas ; yet they are both vapors, the one derived
from a liquid boiling at 35, the other from a liquid boiling at 10.
The distinction is thus determined by the trivial condition of the
boiling-point of the liquid, under the ordinary temperature of the
atmosphere. Such a distinction may have some advantages for
practical reference, but it has no scientific value. The critical
point of temperature affords a criterion for distinguishing a vapor
from a gas, if it be considered important to maintain this dis-
tinction at all. Many of the properties of vapors depend on the
gas and liquid being present in contact with one another; and
this, we have seen, can only occur at temperatures below the
critical point. We may accordingly define a vapor to be a gas at
any temperature under its critical point. According to this definition
a vapor may, by pressure alone, be changed into a liquid, and may
therefore exist in presence of its own liquid; while a gas cannot
be liquefied by pressure, that is, so changed b}^ pressure as
to become a visible liquid distinguished by a surface of demarcation
from the gas. If this definition be accepted, carbonic acid
will be a vapor below 31, a gas above that temperature ; ether
a vapor below 200, a gas above that temperature.

" We have seen that the gaseous and liquid states are only dif-
ferent stages of the same condition of matter, and are capable of
passing into one another by a process of continuous change. A
problem of far greater difficulty yet remains to be solved, the
possible continuity of the liquid and solid states of matter. But
this must be a subject of future investigation; and for the present
I will not venture to go be} T oud the conclusion, I have already
drawn from direct experiment, that the gaseous and liquid forms
of matter may be transformed into one another by a series of con-
tinuous and unbroken changes."

SUPERSATUKATION.

Mr. J. G. Grenfell has described several interesting experi-
ments, bearing on the theory of supersaturation. Professor
Tomlinson supposes that a supersaturated solution adheres as a
whole to a chemically clean surface, while to a chemically unclean
surface the salt or gas adheres, while the liquid does not, thereby
liberating the former. Grease is considered to be a cause of
uncleanness. If, now, a greasy surface can be rendered inactive,
either grease is not a cause of uncleanness, or unclean surfaces
are not necessarily inactive. A number of experiments were
tried, in which a drop of melted fat was allowed to fall on a super-
saturated solution, without causing solidification even upon agita-
tion of the liquid, while a minute crystal of the salt caused instant
solidification. Mr. Tomlinson's explanation, then, would seem
to be inadequate. M. Gerney believes that only a crystal of the

134 ANNUAL OF SCIENTIFIC DISCOVERY.

same salt can induce crystallization, a view necessitating our be-
lieving that ail salts capable of supersaturation are everywhere
present in the atmosphere. Some other experiments seem to show
that a supersaturated solution may remain unchanged for a long
time in an atmosphere saturated with the same salt. We must
probably conclude that supersaturated solutions really contain the
anhydrous salt in a state of unstable equilibrium, only requiring
a disturbance to cause it to assimilate water, and thus produce a
less soluble compound. Prof. Tomlinson, in a later paper, con-
siders oils and fatty matters as chemically clean when they con-
tain no matter foreign to their composition. The oils, however,
whether clean or not, seem to act as powerful nuclei when in the
form 'of thin films/ He also remarks regarding M. Gerney's views
that when that physicist so carefully prepared his nuclei as to be
absolutely free from salt, he also made them chemically clean.

VELOCITY OF SOUND.

M. Andre, in " Comptes Rendus," gives an account of some
experiments made by him relative to the velocity of sound in
water contained in a cast-iron conduit. Having the charge of lay-
ing a tubular conduit, which had to be tested by pressure when
filled with water, it occurred to him to make some fresh measure-
ments on the velocity of sound in that medium. The conduit con-
sisted of cast-iron tubes of 0.8 metre internal diameter and 0.02
metre thick, forming when joined a straight line of about 600
metres. The motions of the liquid were recorded by means of a
kind of pneumatic register, the disturbance communicating itself
to the air confined in a small caoutchouc tube, and thence to a
membrane of gold-beater's skin. A very delicate lever fastened
to this membrane indicated, by its oscillations, the slightest move-
ments of the liquid. The time was measured by means of a
tuning-fork, which inscribed its vibrations on the blackened sheet
of a registering cylinder. This tuning-fork gave for a tempera-
ture of 20, 256 vibrations per second.

A series of experiments was first performed to ascertain the
velocity in air using the same apparatus, and producing the
sound by means of a pistol charged with one gramme of powder.
The shock communicated to the air of the conduit was propa-
gated through the whole length of the tubes, and then returned

^? ^j ^j

after reflection. At each successive departure and return, the
style of the membrane gave very distinct indications on the reg-
istering cylinder.

The temperature of the air in the tubes was 40 at one end and
20 at the other, as they were laid in an open trench upon part of
which the sun shone. Taking these two numbers as extreme
limits of temperature, the velocity of sound ascertained when re-
duced to zero was,

V zz: 326.60 metres, if temperature was 40 ;
V = 337.50 metres, if temperature was 20.

It is certain that the first number must be nearer the truth than

NATURAL PHILOSOPHY. 135

the second ; for the part of the tubes exposed to the sun was con-
siderably greater than that in contact with the cold ground.

The interior being filled with water and completely freed from
air, experiments were made on the velocity in water. The
shock was produced by suddenly forcing in the piston of a hy-
draulic press. However rapidly the pump-lever was lowered,
no shock, properly so called, was produced, but a gradual com-
pression ; thus the indication of the style upon the register, in-
stead of being a well-defined zigzag, as in the case of air, traced
an elongated curve, of which the point of coincidence with the
spiral inscribed by the style at rest was difficult to determine.

Four successive experiments gave a mean of 345 vibrations of
the tuning-fork between the initial and return shocks. The
length of the conduit between the two plates which closed the
extremities was 603.25 metres ; hence the distance travelled by
the compression between departure and return was 1,206.5
metres. The temperature of the water at the top of the conduit
was 20, and 13 at the bottom. The temperature of the sur-
rounding air was 18. Under these circumstances the velocity of
the compression was found to be 897.80 metres per second.

Wertheirn deduced from the sound given by brass organ-pipes
dipping in water, 1,173 metres per second as the velocity of sound
in water. This number is much less than 1,435 metres per
second, found by M.M. Colladon and Sturm, in direct experi-
ments made on the Lake of Geneva.

The value which M. Andre found is still further from the
number observed in an indefinite mass of water.

The author calls the attention of physicists to the influence which
the elasticity and friction of the containing sides may have on the
propagation of a shock in the midst of an almost incompressible
fluid.

FIXED NOTES CHARACTERISTIC OF THE VARIOUS VOWELS.

BY 31. R. KOENIG.

" According to the researches of MM. Donders and Helmholtz,
the mouth, arranged for the emission of a vowel, has a note of
stronger resonance, which is fixed for each vowel, whatever may
be the fundamental note on which it is given. A slight change
in the pronunciation modifies the vocal notes so sensibly that M.
Helmholtz has been able to propose to linguists to define by these
notes the vowels belonging to the different idioms and dialects.
Hence it is of great interest to know exactly the pitch of these
notes for the different vowels. M. Donders sought to arrive at
this by observing the rustling or whistling which the current of
air produces in the mouth when the different vowels are whis-
pered; the notes which he has found differ considerably from
those given by M. Helmholtz. The latter used a set of tuning-
forks, which he made to vibrate in front of the mouth when it was
arranged to articulate a vowel. Every time the sound was
strengthened by the air enclosed in the cavity of the mouth, this
mass of air was evidently in unison with the tuning-fork. By

106 ANNUAL OF SCIENTIFIC DISCOVERY.

tliis method, which is more correct than the first, M. Helmholtz
found that the vowel A was characteristic by the fixed note
(sib)4 , O by (sib) 3 , E by (sib)s , and these results really appear
incontestable. As none of the tuning-forks arranged was suffi-
ciently acute for the vowel I, M. Helmholtz tried to determine
the characteristic note by the means already employed by M.
Bonders, and found it to be re 6 . If a tuning-fork be tuned for
this note, we ascertain, in fact, that it is increased whilst the
mouth passes from E to I, at least I have been able to assure
myself that the increase occurs before the mouth is exactly ar-
ranged for I. Hence the time characteristic of I must be higher.
By constructing tuning-forks more and more acute, I ascertained
that this note was approached; it was finally found to be (sib) G ;
with tuning-forks still higher it is immediately felt that the limit
has been passed.

" For OU, M. Bonders has given fa 3 . This note can undoubt-
edly be strengthened by the mouth, but it is only in departing
very little from the position O, and one feels that the note for
OU must be much more grave. M. Helmholtz assigns fa 2 to OU.
However a tuning-fork, fa2 , does not resound before the mouth
arranged for OU, which M. Helmholtz accounts for by the small-
ness of the opening of the mouth ; but it seemed to me that this
smallness of the opening, while rendering a very energetic in-
crease impossible, must still admit an appreciable increase in the
intensity of the sound. Having, moreover, ascertained the sim-
ple ratios which exist between the notes of the vowels, O, A, E,
I, ascending by octaves, I thought that this law would extend to
the vowel OU. I verified this hypothesis circumstantially by
means of a tuning-fork, the pitch of which could be raised by
means of slides : 1 was thus able to assure invselt'that the charac-

7 /

teristic note of OU (as I ordinarily pronounce it) was really
(sib) 3 ; for the maximum of resonance always occurred between
440 and 460 simple vibrations.

"For the pronunciation of the Germans of the North (to which
the experiments of M. Helmholtz also refer), the vowels are
then characterized as follows :

OU O A E I

(sib) 2 (sib) 3 (sib) 4 (sib) 5 (sib) 6 ;

or, in round numbers of simple vibrations, 450, 900, 1800, 3, GOO,
7,200.

" It seems to me more than probable that we must seek in the
simplicity of these ratios the physiological cause which makes us
find nearly always the same five vowels in the different lan-
guages, although the human voice can produce an indefinite
number, as the simple ratios between the numbers of vibrations
explain the existence of the same musical intervals among most
nations." Philosophical Mag. from Comptes Bendus.

NEW MODE OF HEATING STONE-WARE VESSELS.

Mr. J. A. Coffey has patented a new method of heating stone-
ware vessels and of obtaining regulated high temperatures, which

NATURAL PHILOSOPHY. 137

will be of value in manufacturing chemistry. The principle is to
cause a current of heavy paraffin e oil to circulate, first through a
coil of pipes in a furnace, and then through the jackets of the
pans. It moves by its own convection. Any temperature from
100 to 700 Fahrenheit can easily be obtained. As contrasted
with steam heat, the inventor claims for his process a saving of 80
per cent, in fuel, the large amount of heat necessary to convert
water at 212 into steam being economized.

DEEP-SEA THERMOMETERS.

Capt. Richards, R.N., Hydrographer of the Admiralty, has
made a number of experiments regarding the inaccuracy of ther-
mometric measurements at great depths. As it is well known
that a delicate thermometer is affected in vacuo, it was naturally
supposed that an opposite effect would take place under in-
creased pressure. The experiments were performed with a hy-
draulic press. Previous to the experiments, Dr. W. A. Miller
proposed a mode of protecting the bulb from compression by en-
casing the full bulb in glass, the space between the case and bulb
being nearly filled with .alcohol. A wrought-iron bottle had been
made to contain a thermometer, for the purpose of comparison
with those subjected to compression, but it burst under the great
pressures employed. Those designed by Dr. Miller, however,
showed so little difference under pressure that they were received
as standards. Two series of experiments were then made at
pressures equal to depths of 250, 500, etc., to 2,500 fathoms, the
results of which satisfactorily proved that the strongest-made un-
protected thermometers are liable to considerable error, and
therefore that all previous observations made with such instru-
ments are incorrect. Experiments were also made in the testing
apparatus, with Sir William Thompson's enclosed thermometers,
to ascertain the calorific effect produced by the sudden compres-
sion of water, in order to find what error, if any, was due to
compression in the Miller pattern. An error was proved to exist,
but small, amounting to no more than 1.4 under a pressure of
3 tons to the square inch. The dredging cruise of the "Por-
cupine " afforded an opportunity of comparing the results of the
experiments made in the hydraulic testing apparatus with actual
observation in the ocean. The result was, that though there was
a difference in the curves drawn from the two modes of observa-
tion, still the general effect was the same, and the means of the
two were identical. From these experiments and observations a
scale has been made, by which observations made by thermome-
ters of similar construction to those with unprotected bulbs can
be corrected and utilized. It is suggested, that to avoid error
from the unsatisfactory working of the steel indices of self-regis-
tering thermometers, two instruments should be sent dow^i at
each observation ; and, although their occasional disagreement of
record may raise a doubt, a little experience will enable the ob-
server to detect the faulty indicator, while their agreement will
create confidence.
12*

138 ANNUAL OF SCIENTIFIC DISCOVERY.

EMISSION, ABSORPTION, AND REFLECTION OF VARIETIES OF
HEAT RADIATED AT LOW TEMPERATURES.

Magnus has communicated an interesting and valuable paper
on the heat radiated at low temperatures, and on the absorption
and reflection of such rays. The* results of this investigation
the last, we suppose, made by the lamented author are, so far
as published, in his own words as follows :

" (1.) Different bodies at 150 C. radiate different kinds of
heat. These kinds of heat are more absorbed by a substance of
the same kind as the radiating body than by others, and this ab-
sorption increases with the thickness of the absorbent.

*' (2.) There are substances which emit only one or a few kinds
of heat, others which emit many kinds.

" (3.) To the first of these belongs rock salt when quite pure.
Just as its ignited vapor, or that of one of its constituents, sodium,
radiates but one color, so rock salt, even at a low temperature,
emits but one kind of heat. It is monothermic, as its vapor is
monochromatic.

" (4.) Rock salt, even when quite clear, emits, together with its
peculiar rock-salt heat, heat which is not more absorbed by a
plate of rock salt 80 mm. in thickness than by one 20 mm. in
thickness.

" (5.) Rock salt absorbs very powerfully the heat Avhich it
radiates. It therefore does not, as Mellari supposed, allow all
kinds of heat to pass through it with equal facility.

" (6.) The great diathermancy of rock salt does not depend
upon its less power of absorption for different kinds of heat, but
upon the fact that it radiates only one kind of heat, and conse-
quently absorbs only this one, and that almost all other substan-
ces send out heat containing only a small fraction or more of the
rays which rock salt emits. But all rt\,ys which differ from those
radiated by any substance are not absorbed by it, but pass
through with undiminished intensity.

" From this we may infer that any substance is diathermanous,
only because it radiates but few waves of quite definite length,
and consequently absorbs only these, allowing all the others to
pass through.

" (7.) Sylvin behaves like rock salt, but is not monothermic to
the same extent. In the case of this substance also, an analogy
exists with its ignited vapors, or those of potassium, which, as is
well known, yield a nearly continuous spectrum.

"(8.) Fluor-spar completely absorbs pure rock-salt heat ; we
ought, therefore, to expect that the heat which it emits will be
equally absorbed by rock salt. Nevertheless, 70 per cent, of this
heat passes through a rock-salt plate 20 mm. in thickness. This
may doubtless be easily explained with reference to the quantity
of heat which fluor-spar emits in comparison with that of the rock
salt; still it is possible that fluor-spar at 150 emits rays other
than those which it absorbs at ordinary temperatures. This be-
havior is probably connected with the great reflecting power of
fluor-spar for rock-salt heat.

NATURAL PHILOSOPHY. 139

" (9.) If it were possible to produce a spectrum of the heat
radiated at 150 C., the spectrum would, if rock salt were the radi-
ating body, exhibit only one luminous band. If sylvin were used
as a radiator, the spectrum would be much more extended, but
would still occupy but a small portion of the spectrum which the
heat reflected from lamp-black would form."

In concluding this part of his memoir Magnus makes some re-
marks on transparency, which seem to us very suggestive. If we
assume that there is a constant interchange of heat even between
bodies having the same temperature, we may fairly assume also
that there is such an exchange in the case of light. We cannot
observe the light which bodies emit, at ordinary temperatures,
but they do not absorb light, since this absorption produces their
colors. If such an exchange of light takes place at ordinary tem-
peratures, it would follow that transparent bodies cither radiate
only such rays as are not contained in the light emitted by ignited
bodies, and then they absorb none of these rays, or they emit
only one or a few of the wave-lengths of the light which is visible
to us. Since, then, they absorb only these, and allow all others to
pass through, so that the intensity of the transmitted light is but
little less than that of the incident light, we may therefore infer
that the transparency of bodies depends upon the fact that they
radiate only a few of the wave-lengths, which are contained in
the light known to us. Sillimaii's Journal, from Poggendorff.

USE OP THE ELECTRIC CURRENT IN CALORIMETRY.

BY M. J. JAMIN.

"Joule's Law gives the heat which is developed in conductors
when traversed by currents. A metal wire may be regarded as
a focus. It may have any possible form and be placed where we
please, in the midst of liquids or gases ; a quantity of heat will be
given off proportional to the time, to its resistance, and to the
square of the intensity of the current. It will heat these bodies
by a quantity that can be measured, and which is inversely pro-
portional to their mass and to their specific heat. Hence results
a new process to determine this specific heat. After numerous
trials I fixed upon he following arrangements :

"I. Case of Solids and Liquids. In dealing with a solid or a
liquid, I use as a calorimeter an elongated cylindrical vessel of
thin copper, on which is coiled 8 metres : of German-silver
wire 0.2 millim. in diameter, and covered with silk. This spiral
commences at the bottom of the vessel, and ascends to one-third
of its height ; it is connected with the circuit by thick copper wires ;
its resistance is measured for all the temperatures of the experi-
ment. I envelop it with a thick silk ribbon to keep it in its
place, some swan's down to insulate it, and I enclose the whole in
an envelope of thin copper polished. When the calorimeter con-
tains a liquid, and a current is caused to pass through the spiral,
nearly all the heat will be transmitted to the side, then to the
liquid ; a scarcely appreciable portion will be transmitted to the
swan's down.

c '

140 ANNUAL OF SCIENTIFIC DISCOVERY.

** With this view, fresh liquid must continually be brought into
contact with the sides by uniform agitation. For this purpose, a
basket, of metal gauze, formed of 2 concentric tubes, is im-
mersed in the calorimeter. A small machine raises it and lowers
it at equal intervals ; a thermometer marking the hundredth of a
degree is immersed in the central tube ; it is fixed, and is read
with a telescope. When the specific heat of solids is to be
measured, they are placed in the basket in the water.

" This constitutes the entire apparatus ; the operation is one of
extreme simplicity. After pouring into the calorimeter the weight
of liquid which is to be investigated, and agitating it for some
time, the variation (if any) of the thermometer is observed for
5 minutes. Generally it does not vary. A current of measured
intensity is then made to pass during 1, 2, etc., minutes, until an
elevation of 3 or 4 degrees is produced ; this is noted, after which
the cooling of the thermometer is observed during 5 minutes.
The quantity of heat given off is known, the effect it has produced
is calculated, and from the known formulas of calorimetry the
desired capacity is deduced. Thus, suppose two experiments to
be made with the same current during the same time, with the
weights P and P' of water and of the liquid to be studied. The
quantities of heat are the- same ; they have heated the liquids
and 0' degrees. Denoting the weight of the calorimeter reduced
to water equivalents by /r, and the capacity sought by x, we have
(/> -}- TT) = (P f x -f- ;:) (i f , from which x can be calculated.

"The old method required two operations, which were, the
first, to heat in a stove for a long time the body to be studied, and
to pour it, with minute precautions, into the calorimeter; the
second, to observe the thermometer immersed in the calorimeter.
In the method which I propose the first operation is omitted, and
the second suffices such as it was before. The corrections remain
the same, but are simplified.

" They are simplified, because a lower temperature is sufficient,
and because the heat given off being proportional to the time,
the method known as Rumford's is applicable. We may even
dispense with all correction, as I shall show.

"I provided the external envelope of the apparatus with a
spiral 20 times as long as the first, and immersed the whole in a
vessel containing 20 times as much liquid as the calorimeter, and
forming a medium in which the latter is immersed. The current
passes simultaneously into the 2 spirals ; it produces there heats
proportioned to the quantities of liquids, and consequently equal
heatings. At each moment the temperatures of the calorimeter
and its surroundings are in equilibrium, and the first, neither los-
ing nor gaining anything by radiation, is subject only to the action
of the current. It is impossible to maintain this equilibrium
strictly during the whole time of the experiments if they are pro-
longed ; but it is very easy to establish it within a few tenths ; and
this is sufficient to obviate all necessity for correction. Thus we
can measure for each degree the specific heat of a liquid (water or
alcohol, for example) from the lowest temperatures to its boiling-
point.

NATURAL PHILOSOPHY. 141

"I have verified this method by determining the capacities of
iron and of copper, which are the most difficult to obtain exactly,
because they are very small. I found 0.098, 0.093. M. Regnault
obtained the numbers 0.113, 0.095, which are a little larger ; but
he operated with a higher temperature.

"II. Of Oases and Vapors. The advantages of this method
are especially apparent when treating of aeriform fluids. A gas-
eous current passes through a glass tube to the middle of a cork
of badly conducting material ; a thermometer there measures its
temperature. It immediately enters a second tube through the
folds of a metal spiral or a bundle of twisted wires traversed by
electricity, that is to say, through a focus; it becomes heated
and meets a second thermometer, which measures its increase of
temperature. Before emerging, the gas is led round the first tube,
to prevent any loss by radiation and conductibility ; and when the
temperature has become stationary, we may say that all the heat
of the focus, which is known, is taken by the gas, the tempera-
ture of which is increased by a measured quantity ; hence the
specific heat can be deduced.

" There are two advantages in this method. The first is, that
the greatest cause of error which Delaroche and Berard, and after-
wards M. Regnault, met with, is suppressed. In their experi-
ments the gas reached 100 in a calorimeter at 10 ; and the great-
est difficulty was felt in appreciating the heat which passes by
conductibility from the hot tube to the cold calorimeter. In my
method the gas reaches, at the ordinary temperature, say 10 ; it
passes from the spiral at about 20 ; the difference is 10 ; it Avas
90 before ; the present error is at most one-ninth of the former.

"Here is the second improvement. The whole of my appara-
tus is the size.of a finger ; it is of thin glass ; it might be of mica,
even of goldbeater's skin ; it weighs no more than a litre of gas,
and expends no more heat in reaching the final temperature. Ten
litres of gas are sufficient to make one measurement. Thus the
difficulties that had for a long time to be overcome, in order to
obtain a uniform current, disappear, ordinary gasometers suffice,
and the method is applicable even to vapors. A first determina-
tion gave the number 0.242 for air instead of 0.237, which M.
Regnault found.

" Thermometers, even, may be dispensed with, and the tem-
perature measured by the increase of resistance in the wires. It
is known that a resistance r at zero becomes r (1 -f- at) at t de-
grees. That bein<* the case, let 2 equal bundles of wires be placed
one after another in a tube ; then, having decomposed the total
circuit into 2 equal derived circuits, let us make each of them
pass, first, through 1 of the 2 bundles of wires, then into a differ-
ential galvanometer ; the latter remains at zero. But if a current
of gas at t degrees be sent through this tube, it will pass at t -\- 9 in
the first spiral, at t-\-29 in the second ; they take a difference of
temperature 0, a different resistance, and the galvanometer is
deflected. It is reduced to zero on introducing, by means of a
special rheostat, a platinum wire into one of the circuits. The

142 ANNUAL OF SCIENTIFIC DISCOVERY.

length of this wire is proportional to the increase of temperature
S ; it admits of measurement.

" The same apparatus is applicable to vapors. The liquid to be
examined is distilled as regularly as possible ; the current of
vapor is at first superheated by the first bundle of wires ; it after-
wards traverses the second, becomes heated by a quantity 0,
which is measured as before ; the vapor is condensed, and after-
wards weighed. In order to take into account the irregularities
of the distillation, it is necessary to observe the apparatus from
minute to minute.

"III. Latent Heat. In order to measure latent heats, a
double alembic is employed, of which one part is exterior ; the
liquid in it is caused to boil, and the vapor is brought there after
having been condensed by a refrigerator ; the effect of this is sim-
ply to raise to the boiling temperature the interior alembic,
which contains the same liquid, and in which is immersed the
spiral, the resistance of which is known for every temperature.
The vapor which forms in the second apparatus is collected dur-
ing 10 minutes before the passing of the current; there is scarcely
any ; the circuit is then closed which determines a rapid boiling.
The heat supplied is known ; the vapor which it has formed with-
out change of temperature is weighed, and the latent heat is
deduced.

" IV. TJie two Specific Heats. A third application of the same
principle can be made. In a large bell-glass filled with air, a
metal wire is stretched ; an intense current is passed for a short
time through it. which develops a determined quantity of heat ;
a fraction of this disappears by radiation ; the remainder, which
is constant, gives heat to the gas, which can be measured in two
ways, either by increase of the volume at constant pressure, or
by increase of the pressure at constant volume. From these two
effects the ratio of the two specific heats can easily be determined,
and the number found is about 1.42, a number indicated by the
velocity of sound." Comptes Rendus, trans, in Phil. Mag.

SUDDEN BREAKING-UP OF ICE.

A letter from Canada, in " Nature," for June 23, gives some
curious facts regarding the sudden breaking-lip of ice coverin^

^j <-J ^j i. ^5

lakes and rivers. " The ice on our inland lakes is generally 2 or
3 feet thick. As the spring advances, an inch or two may be
melted away from the lower surface, and somewhat more from
the upper one, but the thickness is not materially reduced until
its final disappearance. The first sign of the approaching break-
up is that the ice becomes dry, from the prismatic structure hav-
ing commenced to show itself, allowing the surface water to
percolate through the interstices; it is then said to be honey-
combed. In this state the lower layers of transparent ice are still
solid, though if you cut out a block the prismatic structure is very
evident; but the upper portion, which has been formed from a
mixture of snow and water, readily breaks up under your feet in-

NATURAL PHILOSOPHY. 143

to little granules of ice. The next stage is that the ice becomes
black, showing that it is soaked, as it were, with water; and if at
this time there is any open water, as where a river falls into a
lake, and wind enough to produce a swell, the whole surface of
the ice may be observed to undulate. If the ice now breaks up
prematurely with a high wind, it becomes a mass of spiculce of
ice which have not reached the melting-point, and which I have
seen accumulated to the depth of 6 or 7 feet against the
edge of the ice which has not yet broken up. But if there is no
wind the whole surface of the lake may appear an unbroken sheet
of black ice, still a couple of feet thick, till, in an astonishingly
short time, sometimes not more than a few minutes, it disappears
as if by magic. So sudden is this disappearance that the ice is
popularly believed to sink.

" I once had a very good opportunity of noticing this sudden
disappearance. I had built on the ice during the winter a pier of
logs tilled with stones, and when the spring came it settled down
to the bottom, carrying with it a large cake of the ice. When the
lake had opened, I went round the pier in my canoe to see if it
had settled evenly. There, at the bottom, in 6 or 7 feet of water,
lay the cake of ice it had carried down, with the chips made in
building the pier still imbedded in it ; and, as I looked, blocks
would break off, of a foot or more in thickness, rise to the surface,
and almost instantaneously disappear The true ex-
planation of the prismatic structure appears to me to be the lines
of air-bubbles. These are visible in all ice before any thaw has
commenced, and in the process of freezing they seem to be formed
in vertical lines. When the thaw occurs these lines of bubbles
form the centres, as it were, from which it penetrates in every
direction through the mass."

o

REFRACTION AND DISPERSION OP OPAQUE BODIES.

The results of a research on the relation of the refractive in-
dices and dispersion of opaque bodies, published in Poggendorff's
" Annales," by Wernicke, are thus given by the author :

The examination of thin plates giving colors by interference,
leads to the conclusion " that all bodies of strong dispersion have
optical properties in common, which appear of interest for the
theory of light.

" It is known from experience that dispersion and absorption are
related to one another ; and Cauchy, in his ' Memoire sur la dis-
persion de la Lumiere,' has given an equation in which this re-
lation is implicitly contained. The discussion of this equation, of
which one side is an infinite series, presents some difiiculties; it
has been thought sufficient to retain the first two terms of this series,
and neglect the rest. This would be permissible, as M. Christof-
fel has shown, if in every case the sphere of action were infinitely
small in comparison with the wave-length. That the last as-
sumption is not admissible, however, the discussion of the incom-
plete equation shows ; for it yields the result that every spectrum

144 ANNUAL OF SCIENTIFIC DISCOVERT.

is bounded at the violet end by a visible beam of definite refrac-
tion. This inference is a physical absurdity, since it presupposes
the existence of bodies, which, under any arbitrary angle of in-
cidence, totally reflect a visible beam, or completely absorb it on
the surface. The dispersion-formula derived from the imperfect
series, even if correct for large wave-lengths, can offer no ex-
planation as to what really occurs at that^ limit at the more re-
frangible end of the spectrum.

"While this limit, with substances of weak dispersion, would
lie very far in the ultra-violet, it sometimes appeared in the green
in the bodies which I investigated. With no single body of this
group were even traces of interference observed in the violet.
The reason of this phenomenon might be sought in a strong reflec-
tion of these rays at the surface, or in a strong absorption in the
interior. It has been shown that the latter is the preponderating
cause of the absence of interference-bands. Then they always
vanish gradually with increasing thickness, from the violet to the
red end of the spectrum, and are very soon only present in the
yellow and red. Hence tlie absorption increases with decreasing
ivave-lengths, and, indeed, continuously so for a certain position in the
spectrum, which is special to each substance, and so quickly that on
the other side of it no ray can pass through a layer of the thick-
ness of half a wave-length.

"Hence, in transmitted light sufficiently thick layers of bodies of
pre-eminent dispersion always appear yellow-red or red. I have
sought in vain for a substance of this kind which would be trans-
parent with green, blue, or violet light.

" To meet any objections to these matters of fact arising from
the mention of apparent exceptions, I must make the following
remarks :

" Thin kiyers can be prepared in different ways, which strongly
absorb the light, and are transparent to other than yellow or red
light; such layers, however, like glass coated with soot, are not
to be regarded as bodies, but as loosely connected apparatus of
individual particles, and can only be quoted as exceptions if it
be proved generally that they possess refractive and dispersive
properties. For example : let chlorine, bromine, iodine, sul-
phur-vapor, or sulphuretted hydrogen act on thin layers of
silver ; then thin layers of chloride, bromide, iodide, or sulphide
of silver are formed, which, in comparison with the metals and
metallic oxides described, are very transparent, and show in
the spectroscope beautiful interference-bands. If, however, the
intensity or duration of the action of these agents exceeds a cer-
tain limit, the structure of the layers is destroyed ; the same are
then to be regarded as aggregates of many particles (in several
cases microscopic crystals), although they appear to the eye as
coherent masses ; they are more opaque than the metal itself,
and show no trace of interference-bands in the spectroscope."
Philosophical Magazine.

NATURAL PHILOSOPHY. 145

BREADTH OF SPECTRAL BANDS.

Lippich has attempted the application of the dynamical theory
of gases and vapors to the explanation of the breadth of the bands
of gaseous spectra. The assumption made is that " if it be neces-
sary to consider a molecule as a system capable of vibration, the
spectrum of an ideal gas in which the molecules could be per-
fectly free elastic systems could consist only of a number of differ-
ently colored bands of homogeneous light if the vibratory motions
of the molecules alone be taken into account." But as, according
to the theory of Clausius, the molecules have also very rapid pro-
gressive motions, the refrangibility of the rays produced will
depend upon the combination of the vibratory and progressive
velocities, thus showing the dependence of the breadth of the
bands upon the temperature and density of the ignited gas. The
author gives a law regarding the ratio of the mean and extreme
wave-lengths of the bright bands and dark lines of the same and
different gases.

The comparison of the relative breadth of bands may lead
to some important conclusions. The proximity of bands of
different breadths in anj 7 spectrum may indicate the presence of
gases of different densities or of the same gas in different allo-
tropic states. For example, the faint blue lines in the oxygen
spectrum may indicate the presence of the denser ozone. The
breadth of the spectral bands in the same gas will permit a con-
clusion as to the temperature, a fact useful in stellar spectro-
scopy, there being noticeable differences in the breadth of the
hydrogen bands. The author remarks finally that his conclu-
sions apply only to perfect gases, and changes from these to
vapors will be noticed by changes in their spectra.

INTENSITY OF ACTINISM AT DIFFERENT ALTITUDES.

A paper has been presanted to the Royal Society by Messrs.
Roscoe and Thorpe, giving the results of a series of determina-
tions of the chemical intensity of total daylight under different
altitudes of the sun. The experiments were made on a flat table-
land near Lisbon. The method used was founded on the exact
estimation of the tint which standard sensitive paper assumes
when exposed for a given time to the action of daylight. The
experiments were made as follows :

1. The chemical action of daylight was observed in the ordi-
nary manner.

2. The chemical action of the diffused daylight was then
observed by throwing on to the exposed paper the shadow of a
small blackened brass ball placed at such a distance that its
apparent diameter, seen from the position of the paper, was
slightly larger than that of the sun's disc.

3. Observation No. 1 was repeated.

4. Observation No. 2 was repeated.

The mean of observations 1, 2, 3 and 4 was then taken.

146

ANNUAL OF SCIENTIFIC DISCOVERT. \

The sun's altitude was determined by a sextant and artificial
horizon immediately before and immediately after the observa-
tions of chemical intensity, the altitude at the time of observation,
being ascertained b} 7 interpolation.

One of the 134 sets of observations was made as nearly as
possible every hour, and they thus naturally fall into 7 groups,
viz. :

(1) Six hours from noon, (2) 5 hours from noon, (3) 4 hours
from noon, (4) 3 hours from noon, (5) 2 hours from noon, (6)
1 hour from noon, (7) noon. Each of the first 6 of these groups
contains 2 separate sets of observations (1) those made before
noon, (2) those made after noon. It has before been pointed out,
from experiments made at Kew, that the mean chemical intensity
of total daylight for hours equidistant from noon is the same.
The results of the present series of experiments prove that this
conclusion holds good generally ; and a table is given showing
the close approximation of the numbers obtained at hours equi-
distant from noon.

Curves are given showing the daily march of chemical intensity
at Lisbon in August, compared with that at Kew for the preceding
August, and at Para for the preceding April. The value of the
mean chemical intensity at Kew is represented by the number
94.5, that at Lisbon by 110, and that at Para by 313^.3 light of the
intensity 1 acting for 24 hours being taken as 1000. The follow-
ing table gives the results of observations arranged according to
the sun's altitude :

No. of Observations.

15

18

22

22.

19

24

11

Mean Altitude.
/

9 51

19 41

31 14

42 13

53 09

61 08

64 14

Chemical Intensity.

Sun.

Sky.

Total.

0.000

0.038

0.038

0.023

0.063

0.086

0.052

0.100

0.152

0.100

0.115

0.215

0.136

0.126

0.262

0.195

0.132

0.327

0.221

0.138

0.359

Curves are given, showing the relation between the direct sun-
light (column 3) and diffuse daylight (column 4) in terms of the
altitude. The curve of direct sunlight cuts the base line at 10,
showing that the conclusion formerly arrived at by one of the
authors is correct, and that at altitudes below 10 the direct sun-
light is robbed of almost all its chemically active rays. The re-
lation between the total chemical intensity and the solar altitude
is shown to be represented graphically by a straight line for al-
titudes above 10, the position of the experimentally determined
points lying closely on the straight line.

A similar relation has already been shown to exist (by a far less
complete series of experiments than the present) for Kew, Hei-
delberg, and Para ; so that although the chemical intensity for
the same altitude at different places and at different times of the
year varies according to the varying transparency of the atmos-
phere, yet the relation at the same place between altitude and in-

NATURAL PHILOSOPHY. 147

tensity is always represented by a straight line. This variation
in the direction of the straight line is due to the opalescenee of
the atmosphere ; and the authors show that, for equal altitudes,
the higher intensity is always found where the mean temperature
of the air is greater, as in summer, when observations at the
same place at different seasons are compared, or as the equator is
approached, when different places are examined. The differen-
ces in the observed actions for equal altitudes, which may
amount to more than 100 per cent, at different places, and to
nearly as much at the same place at different times of the year,
serve as exact measurements of the transparency of the atmos-
phere.

The authors conclude by calling attention to the close agree-
ment between the- curve of daily intensity, obtained by the above-
mentioned method at Lisbon, and that calculated for Naples by a
totally different method. Philosophical Magazine, July, 1870.

PHOTOGRAPHY AND MOLECULAR PHYSICS.

Mr. Harrison, in "Nature," calls attention to the facilities of-
fered for studying molecular physics in connection with the
mechanical operations connected with photography. If 3
collodionized plates be dipped, one in a solution of oxide of cad-
mium, the second in a solution of bromide of cadmium, the third
in a solution of chloride of cadmium, as is done in " iodizing " the
plate, and each then sensatized by immersion in a bath of nitrate
of silver, the third will take longer than the second to become
covered with a film of silver salt, and the second longer than the
first. Also, the exposures to light in the camera when used for
taking a picture are in the same order. These differences in time
of exposure may, perhaps, be accounted for on the supposition
that the chlorine binds itself to silver with more force than is ex-
erted by bromine, and that the bromine clings to the silver with
more force than the iodine, so that the waves of light have more
work to do in heating the chlorine from the silver than in separat-
ing the bromine or the iodine. An experiment by Mr. M. Carey
Lea, of Philadelphia, shows that the atoms separated by light may
recombine in darkness. He prepared a film of dry iodide of
silver, on exposing which under a negative, a picture was formed,
which came out on developing with "alkaline developer." If,
however, instead of developing the picture, it was left in darkness
for a few days, the latent image died out, and a new picture could
be taken on the sensitive surface.

MICROSCOPIC PHOTOGRAPHY.

A very successful series of experiments on the production of
photo-micrographs, by means of artificial light, has been con-
ducted by Col. Woodward, of the Army Medical Museum, Wash-

148 ANNUAL OF SCIENTIFIC DISCOVERY.

ington, from the published report of which the following sketch
was made.

During the latter part of 1869, Col. Woodward began a series
of experiments with the design of removing certain difficulties in
the photographing of tissues on a large scale. The solar light
was used, and little difficulty was found in arranging a method
which gave most excellent results. Great annoyance was caused,
however, by the uncertaint} 7 of the weather, there being but few
days suitable for working to advantage. This led Col. W. to
seek some other means of illumination, and by the use of the
electric, magnesium, and lime lights he has succeeded in produc-
ing photo-micrographs with even the highest powers as well or
even much better than by ordinary sunlight.

Two reports have been presented to the surgeon-general ;
the first dated January 4, 1870, concerning the use of the mag-
nesium and electric lights, the second, dated June 4, 1870, con-
cerning the use of the lime light.

The electric light used in the first series of experiments was
produced by 50 small Grove's elements, using a Duboscq's
electric lamp. Not only could photographs be taken on as large
a scale as by sunlight, but the exaggeration of light and shadow
given by the electric light proved most admirably adapted to the
production of clear and well-defined photo-micrographs. The
magnesium light was found to possess many of the excellences
of the electric light, but its best effect is given when the object is
not magnified more than 1,000 diameters.

With the electric light the following method was used in the
production of the photographs :

The electric lamp was placed on a stool against the wall at one
end of the room, and its light concentrated by a pair of condens-
ing lenses on the lower lens of the achromatic condenser of
the microscope. The microscope, a large Powell and Lealand's
stand, was placed on a small table with levelling screws and ar-
rangements for raising and lowering it at pleasure. The lenses
employed were made by Wales, and specially constructed for
bringing the actinic rays to a focus. For powers above the
eighth-inch, the objectives of Powell and Lealand were found to
answer an excellent purpose.

The electric light being arranged and working, the microscope
was moved till the centre of the achromatic condenser and the centre
of the illuminating pencil coincided ; the object was then placed on
the stage and adjusted. A cell of plate glass, filled with a satu-
rated solution of ammonio-sulphate of copper, was placed between
the light and the condenser, thus cutting off a large proportion of
the luminous and calorific rays, besides making the colors of the
object disappear, so that its appearance to the eye was the same
that its photograph would have when taken.

The slide having been arranged, the eye-piece of the micro-
scope was removed, and the image allowed to iall on the ground
glass of the plate-holder, previously placed at the distance giving
the required magnifying power. The objective once carefully
focussed, the sensitive plate was exposed, thus finishing the diffi-

NATURAL PHILOSOPHY. 149

cult portion of the operation. An arrangement was used by
which the objective could be focussed by the operator, when
standing- by the ground-glass plate.

Col. Woodward was thus able to produce from 12 to 30 nega-
tives in an evening's work of 4 hours. About 30 seconds' ex-
posure was found necessary for diatoms and Nobert's plate, when
the object was magnified 1,000 diameters. In photographing
soft tissues, it was necessary to place a plate of ground glass
between the condenser and light to prevent interference-phe-
nomena, which increased the time of exposure for this class of
objects to about 3 minutes. Other powers were found to require
proportional times.

The process employed with the magnesium light is essentially
the same as with the electric light. As this light is composed ot'
a mixed pencil with rays passing in all directions, there are no in-
terference-phenomena caused by it ; but the results with diatoms
are inferior to those by the electric light for the same reason. An
ordinary two-ribbon magnesium lamp was used, and a magic-
lantern condenser served to condense the light in the achromatic
condenser of the microscope. The ammonio-sulphate cell was
used as with the electric light. An exposure of about 3 minutes
was required to produce negatives of tissue preparations with
500 diameters.

Dr. Woodward says further, " In commenting on the above
processes it ma} 7 be remarked that for the anatomist and physio-
logical investigator the magnesium lamp affords a satisfactory and
sufficient source of light for the photography of normal and
pathological tissue preparations. The same end can be equally
well or even better obtained with the electric lamp, with which
also the most difficult test-objects can be satisfactorily reproduced.
Where economy of apparatus is the object, the magnesium lamp
will be preferred by ordinary workers ; but where much work is
to be done, the high price of the magnesium ribbon more than
counterbalances the cheapness of the apparatus, and the electri-
cal light becomes the most economical. For the information of
any practical photographers, who may be employed for work of
this character, I may add the following remarks on the chemical
process employed in the production of the negatives from which
the appended prints were made. An ammonium and potassium
portrait collodion, rich in alcohol, was employed, developed with
the ordinary solution of iron, and fixed with cyanide of potassium.
Where it was necessary to intensify, the hydro-sulphuret of am-
monium was resorted to."

Dr. W. appends to his report 3 prints from negatives of a
" Diatom Type Plate, 11 taken, with a Wales' inch and a half,
intended to illustrate the relative excellences of sunlight, the
light of the magnesium lamp and that of the electric lamp. The
first with sunlight is magnilied 40 diameters, the second taken
with the magnesium light, 48 diameters, the third by the electric
light, GG diameters. " It will be understood at once that, on ac-
count of the increase of distance, the second picture would have
been slightly less sharp than the first, and the third than the sec-

150 ANNUAL OF SCIENTIFIC DISCOVERY.

ond, had precisely the same source of light been employed; never-
theless, in spite of this disadvantage, to which they were purposely
exposed, the magnesium and electric pictures are far superior to
that taken by sunlight, and of the two the electric is the best. It
is especially to be observed that in the electric picture the contrast
obtained is so great that the objects appear clearly defined on an
almost perfectly white ground, which is never the case Avith
photo-micrographs taken with the sun as a source of illumina-
tion."

The second report concerns the use of the lime-light for photo-
micrograpbic purposes. Pictures have been successfully taken
with powers as high as 1,000 diameters. The practicability of the
use of this light islmportant, because of its cheapness, its greater
steadiness, and the little trouble given in its management. In
his experiments Col. W. made the hydrogen as he consumed it,
and sometimes made the oxygen in the ordinary manner, some-
times purchased it compressed in iron cylinders. The lamp used
was a large magic-lantern burner. The magnifying lenses being
removed, a cone of light proceeding from the condenser of the
lantern was allowed to fall upon the achromatic condenser of the
microscope as with the magnesium lamp in the earlier series of
experiments. The ammonio-sulphate cell was used, but the
ground glass required with the electric light was unnecessary.

The time of exposure required was much the same as with the
magnesium lamp, and the pictures are equally good, for though
the actinic power of the naked lime light is less than that of the
magnesium light, the question of steadiness, involving the possi-
bility of great concentration, plays a very important part.

The lime light had never before been successfully employed
thus in this country, though some successful attempts were made
several years ago in England, by a less perfect process than the
one used by Col. Woodward. Experiments have been made in
England by Messrs. Maddox, Abercrombie, and Wilson on the
use of the magnesium light, but no results were obtained compar-
able with those described in the report.

Besides photographs of the sixth square of a Holler's Diatom
Plate by solar, electric, magnesium, and calcium light, Col. W.
presents several other photo-micrographs illustrating the perfec-
tion of the process. Photographed by the magnesium light the
diatom Aracliinoidiscus Ehrenbergii, magnified 400 diameters by
a Wales' one-eighth objective, shows the elegant radiation and
form of the dots with perfect clearness. A second example by
this light is a nitrate-of-silver injection of a small vein and
capillaries in the muscular coating of the urinary bladder of the
frog, also magnified 400 diameters. Four photo-micrographs of
diatoms by the electric light, magnified from 340 to 2500
diameters, show the markings very finely, as does also the admi-
rable photograph of Navicula lyra taken by the lime light. Inter-
esting as showing the perfect success attained in the original
design of the experiments are photographs of an epithelial
cancer of the larynx, magnified 400 diameters by Wales' one-

NATURAL PHILOSOPHY. 151

eighth, and of human red blood-corpuscles magnified 400 diameters
by a Powell and Lealand's one-sixteenth immersion objective.

COLOR-BLINDNESS.

Mr. Monck, of Trinity College, Dublin, propounds a new and
interesting theory of color-blindness. The ordinary explanation
is, that the eye is not sensitive to certain colors, to which it is
objected that a color-blind person sees the whole spectrum, and
that were this explanation true, there should not be color-blind-
ness to complementary colors, red and green for example. Mr.
M. bases his theory on the phenomena of accidental colors. If
the eye be very sensitive to the excitation of the complementary
tint, then this latter, appearing with vividness while we are gaz-
ing upon the original color, is so combined with it as to give rise
to the grayish tint with which color-blind persons so often con-
found colors. The brighter the light, the more quickly and viv-
idly would the accidental color be produced, which explains the
fact that so many Daltonians see better in twilight. Another
argument is, that color-blind persons rarely see accidental colors.
According to this theory, then, the color-blind eye is one in
which the complementary color is seen very rapidly and very
vividly while looking at the primary color. If this view be cor-
rect the Daltoniaii will gain the best idea of a color by a tran-
sient glance at it, and in faint light.

OPTICAL PROPERTIES OF BENZILE.

A paper was read before the Academy of Science (Paris), by
M. Des Cloiseanx, " On the Optical Properties of Benzile and of
some Bodies of the Camphor Family, in the Crystallized State,
and in Solution." The author found that crystals of bcnzile
rotate the plane of crystallization in different ways, and the right
and left crystals, when dissolved and crystallized two or three
times, likewise give a mixture of crystals with opposite rotations.
Solution of benzile in ether has no action or polarized light.
Camphor of patchouli and mint camphor (menthole), both be-
longing to the hexagonal system, have a negative, uniaxial double
refraction, and their solutions in alcohol deviate the plane of
polarization to the left. Three camphors belonging to the cubic
system, namely, Bornean camphor, terecamphine, and mono-
hydrochlorate of turpentine, have no action on polarized light
when crystallized, but in solution strongly deviate the plane of
polarization to the right, the other two to the left.

FIZEAU'S EXPERIMENTS ON " NEWTON'S RINGS."

A comparison of the values of the wave-lengths of the light of
the two principal components of the D line of the solar spectrum, as

152 ANNUAL OF SCIENTIFIC DISCOVERY.

given by Angstrom, with some observations made some years
since by Fizean, shows a remarkable coincidence of results ob-
tained by different methods, and is a new confirmation of the
truth of the undulatory theory of light.

Fizean. produced the phenomenon of Newton's Rings by laying
a convex lens of very long focus upon a piece of glass with plane
parallel surfaces, and illuminating the combination by the mono-
chromatic light of the soda flame. The lens was so arranged
that it could be left to touch the glass or could be separated from
it by a known distance, measured by a micrometer screw. On
separating the lens from the glass plate, the rings were seen to
move in towards the centre of the lens, where they successively
disappeared, while their place was supplied by fresh rings which
made their appearance at the circumference of the lens. Fizeau
found that when the phenomenon was observed with sufficient care
nearly 500 rings could be counted, flowing inwards one after an-
other, but that after about this number the rings ceased to be visible,
the surface of the glass showing a nearly uniform illumination
all over, instead of a sharply defined alternation of light and dark
bands. When, however, the distance between the lens and the
glass plate was further increased, the rings reappeared, getting
gradually more and more distinct, until when nearly another 500
had passed they had become as sharp as at first ; but a still further
increase of distance caused them again to become confused, and
they ceased a second time to be discernible at about the fifteen-
hundredth. With a still greater separation of the glasses, how-
ever, they reappeared again, and became quite sharp at the two-
thousandth, after which, -for a third time, they got gradually
confused, and became indistinguishable at about the twenty-five-
hundredth. So the phenomenon, went on as the glasses were
separated, and not until fifty-two such groups had been counted
did the bands finally cease to be distinguishable. The two glasses
were then separated by an interval of fifteen millimeters, or more
than half an inch.

This remarkable phenomenon of the alternate periods of dis-
tinctness and confusion of the rings is easily explained, as M.
Fizeau points out, when we remember that the light employed
was not strictly homogeneous, but consisted of two portions of
nearly but not quite equal degrees of refrangibility. If either of
these two constituent parts of the light had been used by itself, it
would have produced a set of rings, but the rings of one set would
have been a very little larger than the corresponding rings of the
other. Hence, if the two sets of rings are put together (as they
were in Fizeau's experiments), they will nearly but not quite fit
each other. If we examine a few rings at the centre, when the
two glasses are in contact, they will appear to coincide precisely ;
but if they are traced to a sufficient distance from the centre the
coincidence is seen not to be exact. For although the twentieth
(say) of one set is not perceptibly bigger than the twentieth ring
of the other set, the five-hundredth of one set is perceptibly bigger
than the five-hundredth of the other, and when put upon it falls
almost exactly half way between the five-hundredth and five-

NATURAL PHILOSOPHY. 153

hundred-and-first of this set. Consequently, at about this part of
the phenomenon, the bright spaces of one set of rings will occupy
the same position as the dark spaces of the other sot, and they
will mutually obliterate each other. But since the thousandth ring
of one set is nearly the same size as the thousand-and-first of the
other, the two sets of rings will appear to fit each other again
about this point ; the fifteen-liundredtli of the first set, however, is
larger than the fifteen-hundredth-and-first of the second set, but
not so large as the fifteen-hundred-and-second, and hence, at
about the position of the ring, the rings of the two sets will over-
lap each other, and mutually efface each other's outlines. And,
carrying such considerations further, it is evident that the appar-
ent coincidence and overlapping of the two systems of rings
would occur alternately at regular intervals.

In order to simplify this explanation, we have tacitly assumed
the lens to be so large that several thousand rings could be seen
between its centre and its circumference, Practically, this would
be impossible ; but by gradually separating the lens from the
plane glass, we can, as it were, draw in towards the middle the
rings which, with a larger lens, would be formed at a great dis-
tance from the centre.

Now, according to the explanation which the undulatory theory
gives of the foundation of " Newton's Rings," the distance by
which the interval between the glasses must be increased, in
order that a given ring may come into the position previously
occupied by the next smaller ring, must be equal to half the
wave-length of the kind of light used for the experiment; and
the distance of 0.28945 millimetres which, as M. Fizeau found by
actual measurement, it was necessary to vary the space between
the glasses, in order to make the rings go through one of "the re-
current periods above described, that is to say, pass from sharp-
ness to confusion and become sharp again, must contain just one
more half wave-length of one portion of the light by which the
rings are formed, than it does of the other.

This brings us to the point of contact between M. Fizeau's
observations and those of Prof. Angstrom, to which we referred
at the beginning. According to the latter, the wave-lengths of
the two principal constituents of the light emitted by a flame
containing the vapor of sodium (such as the flame employed by
M. Fizeau) are respectively

0.000589513 millimetres.
0.000588912

Now, if we divide 0.28945 by half the former of these numbers,
we get, as the quotient, 982 ; and if we divide it by half the
second, we get, as the quotient, 983. That is to say, we find
precisely as the undulatory theory requires, that the distance
measured by M. Fizeau contains exactly one more half wave-
length of the more refrangible constituent of the light of a
sodium-flame than it does of the less refrangible part. And,
moreover, if we calculate from Angstrom's determination of the
wave-lengths, the number of rings which must intervene between
the positions of greatest confusion and greatest distinctness, we

154 ANNUAL OF SCIENTIFIC DISCOVERY.

find 491 of the one set and 491 of the other, which agrees en-
tirely with M. Fizeau's estimated round number of 500.
Nature.

ELECTRICAL DISCHARGE.

Prof. Yon Bezolil, in the "Philosophical Magazine," thus sums
up the results of a series of experiments upon the electrical dis-
charge :

'* 1. When an electrical discharge, after traversing a spark-
interval, is offered two paths to the earth (a short one and a long
one interrupted by a test-plate), with small striking distances, the
discharge is divided. With greater distances the electricity takes
only the shorter path, and even carries with it electricity of the
same kind from the other branch.

" 2. If electrical waves be sent into a wire insulated at the end,
they will be reflected at that end. The phenomena which ac-
company this process in alternating discharges appear to owe
their origin to the interference of the entering and reflected
waves.

"3. An electrical discharge travels with equal rapidity in wires
of equal length, without reference to the materials of which these
wires are made."

NEW GALVANIC BATTERY.

A new and important galvanic battery, invented by Bunsen, is
described in Prof. Roscoe's address before the British Associa-
tion. Only one liquid, a mixture' of sulphuric and chromic acids,
is employed, so that no porous cells are needed. The plates of
zinc and carbon can all be lowered at once into the liquid and
raised again at will. The electro-motive force of this battery is
to that of Grove (the most powerful of all known forms) as 18 to
25 ; it evolves no fumes in working, and can be used for a very
considerable length of time without serious diminution of the
strength of the current, so that Bunsen writes that no one who
has once used the new battery will think of again employing the
old forms.

RESISTANCE PYROMETER.

Mr. C. W. Siemens has invented an instrument called an
" Electrical Resistance Pyrometer," which will measure the heat
of the hottest furnace. It is based on the principle that the re-
sistance of pure metals to the electric current increases with the
temperature in a very simple ratio. A platinum wire of known
resistance is coiled round a cylinder of fine clay, and covered
with a tube of the same material. The coil is connected with a
Daniell's battery of 2 cells and with a resistance measurer, and
placed in the furnace whose temperature we wish to ascertain. It
is then only necessary to read olf the indications of temperature
on the graduated resistance measurer.

NATURAL PHILOSOPHY. 155

EXPERIMENTS ON THE ATLANTIC TELEGRAPH CABLES.

The report of the Coast Survey Expedition of 1866, regarding
electrical measurements made on the cables of 1865 and 1866,
has been published in the Smithsonian " Contributions." The
following is a summary of Dr. Gould's conclusions taken from
the " Journal of the Franklin Institute : "

Four leading questions were to be answered by the experi-
ments. 1. The character of the agency which gives the tele-
graphic signal upon the closing or interruption of the galvanic
circuit, and the route by which its transmission is effected.

2. The influence exerted upon the conductor by using the
earth as part of the circuit, or by placing the complete circuit in
electrical communication with the earth.

3. The extent to which the velocity of propagation of the sig-
nals is dependent upon the intensity of the electromotive force,
and upon the resistance of the conductor.

4. The equality or difference in speed of the signals from the
positive and from the negative electrode, when the other is con-
nected with the earth ; as also the relative velocity of signals
given by completing and by interrupting the circuit.

' The length of the cable of 1865 is 2,186 statute miles, and that
of the cable of 1866 is 2,134 statute miles. Each conductor is con-
structed of 6 copper wires twisted round a seventh one, and has
a diameter of one hundred and forty-seven one thousandth
inches. The conducting power of the wire is 93.1 for the cable
of 1865, and 94.6 for that of 1866, the conducting power of pure
copper being 100. The cable of 1865 gave a resistance of 4.01
ohms per knot, the " insulation " or resistance of the coating
being 2,945 megohms per knot, and the electrostatic capacity
0.3535 farad to the knot. That of 1866 gave a resistance of 3.89
ohms per knot, and an insulation of 2,437 megohms, the electro-
static capacity being the same as in the cable of 1865. The total
resistance to conduction in the first cable is, then, about 7,650
ohms, the total resistance of the insulator 1,505,000 ohms,
and the total electrostatic capacity about 670.4 farads. In
the second cable, the total resistance is about 7,270 ohms, the
total insulation 1,316,000 ohms, and the total electrostatic capac-
ity 654.5 farads.

"The battery employed by t the telegraph company was Minot-
ti's, a modified form of DanielFs. Mr. Farmer estimates that
after the full strength of the current is developed, one cell should
give upon one cable with earth-connection about 110 farads
per second.

Several series of experiments were made with varying battery
power, and different arrangements of the connections, in some
using the earth circuit, in others not using it, sending both posi-
tive and negative signals.

The first question to be investigated is, whether the posi-
tive and negative signals were transmitted with the same veloc-
ity. A comparison of the records of the same signals at the two
stations decides this, without the necessity of knowing the abso-

156 ANNUAL OF SCIENTIFIC DISCOVERY.

lute time of transmission. This comparison gives us the interval
T T" (the difference of the time indicated at the same moment
by the two clocks, diminished by the time of transmission in the
case of signals given from Valencia, and increased by this
amount for signals from Newfoundland). Any excess of the
time consumed in the passage of either class of signals should
manifest itself by a superior value in the measures of the tem-
porary clock-difference derived from that class when the signals
are sent westwardly. For earthward signals the reverse holds.
An examination of the recorded results shows that the positive
and negative signals travel with the same velocity under the
same circumstances.

The speed of the two kinds of signals being thus taken as the
same under similar circumstances, the time required for their
transmission is easily deduced, being one-half the difference be-
tween the measures of longitude as derived from the records at
the respective stations. The weak point in the observations is
the absence of any automatic record of signals received, but it is
probable that the aggregate personal error of the two observers is
very close to 0.606% which value is adopted in the investigation.

The experiments of November 5th and 6th were conducted with-
out the use of any earth circuit. Each station sent signals with a
battery of 3 MinottPs cells, receiving them with its battery dis-
connected. The mean interval consumed in the transmission of
the signals appears to have been 0.29 s on the former, and 0.26 s on
the latter occasion.

With a battery of 3 Minotti's cells, the maximum permanent
current would not exceed 168 farads in the joined cables, and to
develop nine-tenths of this current more than 1^ second would be
needed. With 3 DanielPs cells the maximum current would not
exceed 185 farads. Assuredly, we cannot suppose that in the
lapse of three-tenths of a second, when not more than one-seventh
of this current had been developed at the farther station, this bat-
tery would have charged the 2 joined cables, each of which pos-
sessed an electrostatic capacity of more than 650 farads. Hence
the impulse on which the transmission of the signal depends must
have been propagated along the conductor by some other means
than by charging its successive parts electrically, that is, fully
and in the ordinary sense of this expression. The 30 farads, more
or less, which could have been generated before the signal arrived
at the distant extremity of the cables, would have been consumed
in charging the first six or seven hundredths of the conductor.

Messages were effectually and distinctively transmitted in each
direction, by the use of an electromotor formed by a small percus-
sion cap containing moistened sand, upon which rested a particle
of zinc. The current here evolved could scarcely have amounted
to more than 6 or 7 farads, so that nearly 2 minutes would have
been requisite for charging a cable, yet the transmission time was
certainly very small, although it was not definitely measured.

The experiments of November 8th and 9th differed from those
of the 5th and 6th only in that the Newfoundland battery con-
sisted of 10 cells instead of the same number as was employed at

NATURAL PHILOSOPHY. 157

Valencia. The mean times of transmission were 0.25 s and 0.24%
indicating an increase of speed with an increase of electro-
motive power. And, so far as the experiments on these 4 days
are concerned, we might infer that on the complete metallic cir-
cuit formed by the 2 cables, the time for transmitting the signals
through about 3,475 kilometers, or 2,160 statute miles, was not far
from "0.29 s for a battery of 3 cells, 0.26 s for one of 4 cells, and
0.215s for one of 10 cells.

On the other hand, the average transmission time for signals
sent by a current induced in a single cable by means of a " con-
denser," with a battery of 10 cells, was 0.31 s on the 25th, and
0.34 s on the 28th of October; the mean interval on these 2 days
being 0.328 8 . Each of the condensers used possessed an elec-
trostatic capacity of about 20 farads ; so that with a tension of 10
cells or 8.4 volts, their capacity would not be far from 168 farads,
or equal to that of about 590 miles of cable, or, in other words, a
little more than one-quarter the capacity of one whole cable.

Results of recorded signals give 0.26 s as the transmission time
through one cable with earth return, when the ground connection
was made with the zinc, and 0.27 s when it was made with the
middle of the battery, the former corresponding to the use of 4
cells at one statign only, the latter to 2 cells at each station.

The velocity of signals made by closing and interrupting the
circuit is next considered, the conclusion being that in general a
longer time was required for the transmission of signals after an
interval of 10 seconds than after an interval of 5 seconds. In
those cases where no earth-connection existed, and the signals
were alternately positive and negative, the cable was meanwhile
assuming its electrical equilibrium, so that a positive signal was
transmitted more rapidly through the conductor when it was
affected with a larger amount of negative electricity, and a nega-
tive signal more rapidly through a conductor containing more
positive electricity. This affords new testimony to the erroneous
character of the supposition that the conductor must be charged
through any portion of its length, in order to transmit a signal
beyond that portion.

As showing the continued existence of currents (doubtless en-
gaged in establishing equilibrium) during the intervals between
the signals, it may be of interest to mention that on one occasion
when the 2 cables had been joined at Heart's Content, without bat-
tery, and while the Valencia battery had been temporarily discon-
nected, signals from Newfoundland were distinctly received.
They were weak, and the deflections of the needle were scarcely
one-fifth as large as usual, yet they were none the less distinct,
and a complete set of signals, 10 in number, at proper intervals,
and preceded by a " rattle," was recognized at Valencia. No
other record of them was made, than the fact of their transmission
by alteration of the make-circuit and break-circuit signals, although
no battery had been connected with the cable for several minutes.

A series of experiments was made for the purpose of ascertain-
ing the effect of changes in the electro-motive force upon the
speed of the signals, and whether these signals could by the
14

158 ANNUAL OF SCIENTIFIC DISCOVERY.

interpolation of any resistance between them and the gal-
vanometer be made to traverse the double length of the cable
before reaching the galvanometer at the same station.

The construction of the signal-key used in these experiments
was such that only about one-seventieth of a second was oc-
cupied in pressing down the button. All signals by which
currents were sent were given in this way, but the break-circuit
signals were given by removing the thumb from the button,
which was then lifted by the tension of the spring. This tension
being less than the muscular force of the thumb when the
button was pressed down, a longer time was consumed in trav-
ersing the distance between the stops, and for this repeated
experiments give 0.035 s as a near approximation to the average
interval. Now, since the ordinary signals record themselves
upon the chronograph when the arm carrying the button leaves
one stop, but are not really given until it reaches the other, all
the recorded intervals between the instants of giving and receiv-
ing make-circuit signals will be too large by about one-seventieth
of a second, or approximately 0.015 s ; while for break-circuit
signals the reverse obtains, and the recorded interval will be too
small by about 0.035 s . Consequently, in comparisons between
break-circuit signals and others, a correction must be applied,
varying with the temporary adjustment of the signal -key, but
amounting on the average at Valencia to not far from 0.05 8 . This
correction must be borne in mind in drawing inferences as to the
relative velocity of break-circuit and make-circuit currents. Dr.
Gould does not apply it in his tallies, however, because no
measurements were made to determine the pass-time for the
Newfoundland key.

In these experiments the circuit was formed of the two cables
with no other connections than the same ke}^, galvanometer, and
battery at Valencia which had been employed for the other work
of the expedition.

Exp. I. 4 cells. Circuit made and broken. Key between Zincode and gal-
vanometer.

No. Mean Interval,

Make circuits, 11 0.257s

Break circuits, 11 0.229

Exp. II. 4 cells. The same with 126 ohms' resistance between key and gal-
vanometer.

Make circuits, 10 0.279

Break circuits, 9 0.227

Exp. III. 4 cells. Key and galvanometer upon opposite sides of the battery.
Make circuits, 13 0.278

Break circuits, 14 0.225

Exp. IV. 4 cells. The same with 126 ohms' resistance between key and cable.
Make circuits, 11 0.278

Break circuits, 11 0.220

Exp. V. 1 cell. Positive and negative signals.

Positive. Negative. Both.

No. Mean. No. Mean. No. Mean.

2 0.240 8 0.292 10 0.282

Exp. VI. 2 cells. Positive and negative signals.

10 0.249 9 0.242 19 0.246

NATURAL PHILOSOPHY. 159

Positive. Negative. Both.

No. Mean. No. Mean. No. Mean.

Exp. VII. 4 cells. Same.

8 0.268 10 0.290 18 0.279
Exp. VIII. 10 cells. Same.

10 0.270 10 0.245 20 0.258

Exp. IX. 10 cells. Resistance of 25 ohrns interposed between key and gal-
vanometer.

10 0.234 10 0.258 20 0.256

Exp. X. 10 cells. Resistance increased to 251 ohms.

9 0.2S7 10 0.289 19 0.288
Exp. XI. 10 cells. Resistance increased to 2513 ohms.

10 0.305 9 0.28G 19 0.296
Exp. XEI. 10 cells. Resistance increased to 25,130 ohms.

11 ' 0.288 10 0.299 ' 21 0.293

From these experiments it may fairly be concluded :

1. That there was no real difference in the interval for the
make-circuit and break-circuit signals. The mean from the first
4 experiments gives after application of the corrections for
pass-time of the key, an interval 0.261 8 for the make circuits, and
0.260 s for the break circuits.

2. That the relative positions of key, galvanometer, and battery
exerted no perceptible influence upon the result when a battery
of 4 cells was employed. The mean intervals from the first 2
and from the second 2 experiments are 0.258 s and 0.262 s respec-
tively.

3. That no appreciable effect was produced by the interpolation
of 126 ohms 1 resistance. The mean intervals, with and without
this resistance, were 0.258 s and 0.263 s .

4. That no marked diminution of the interval was produced by
an increase of the battery from 2 to 10 cells. The results with 1
cell, although untrustworthy, indicate a somewhat less interval.
The others vary by less than their probable errors, yet the inter-
val was certainly not less with 2 cells than with 10.

5. From the last 3 experiments it would appear that the in-
terval was slightly longer after resistances above 250 ohms had
been introduced. Yet it was no longer in the twelfth experiment
when the resistance between the key and galvanometer was more
than two-thirds greater than the whole resistance of the 2 joined
cables, than in the eleventh, when it was only one-sixth as great
as that of the 2 cables.

6. We have every reason for believing that in all these 12 ex-
periments the measures of the intervals were merely determina-
tions of my own personal equation in noting signals, which, as
has been shown in Chapter IX., had been found by special inves-
tigation to be about 0.275 s . The variations from this value amount
in but few cases to more than 0.03 s , which we have seen to be the
normal range.

7. These experiments are entirely confirmatory of what would
have been anticipated from theory, namely, that a signal given
by closing a galvanic circuit is transmitted in both directions
simultaneously, and with equal velocity under similar circum-
stances; so that under no ordinary practicable circumstances

1GO ANNUAL OF SCIENTIFIC DISCOVERY.

could a signal from either station fail to traverse both parts of the
circuit at that station before passing on to the other.

Since my former investigation (Proc. Amer. Assoc. Adv. Sci.,
1850, p. 71 ; Am, Jour. Sci. xi., 67, 154) the progress of science
has thrown light upon many points which were then subjects of
doubt or of individual opinion. The condition of an open galvanic
circuit is now almost universally conceded not to be essentially
different from that of an interrupted conductor to an electrical
machine. The velocity of a current is also known to be de-
pendent upon its quantity, and therefore generally upon its
intensity, as well as upon the resistance of the conductor. But it
appears questionable whether the law is as simple as has been
supposed by some, who have regarded the velocity as inversely
proportional to the capacity of the conductor multiplied by its
resistance, and, therefore, in a homogeneous conductor to the
square of the length. For the problem, as it now presents itself,
does not pertain so much to the time for transmission of a given
signal, as to the time for its transmission with a certain force,
depending on the sensitiveness of the receiving apparatus; since
the electrical impulse or disturbance consists of a continuous
series of molecular influences which propagate themselves in
every possible direction according to the inverse ratio of their
several resistances. And the form of the conductor, as well as
other conditions, may essentially modify the time requisite for the
attainment of the prescribed force at the other extremity of the
line. A current may thus be temporarily established in part of
an open circuit, continuing until the battery and conductors have
attained an electrostatic equilibrium. The time required for
attaining this equilibrium depends of course simply on the ca-
pacity and form of the conductors, and on the energy of the
battery ; but the first electrical impulse may reach the most re-
mote point of the circuit before a portion nearest the battery has
received its full charge. Similarly, in a closed circuit, the distant
extremity of the line may well be supposed to perceive some
slight electrical disturbance from a signal before its full force is
manifested at intermediate points, so that a signal might be re-
ceived with a delicate galvanometer at the farther extremity,
before it could be recognized upon an electro-magnet at half the
distance. And this, too, apart from any consideration of increas-
ing intensity in the electromotor.

The circuit formed by the two cables might, although broken
at Valencia, thus serve to establish what would practically be a
momentary current at Newfoundland when the battery at that
station was introduced, deflecting the galvanometer there for an
instant, and the change of statical condition in the cables at
Valencia would thereupon be manifest to the electroscope. Bat
the closure of circuit at Valencia would be accompanied by in-
stantaneous deflection of the galvanometer, with corresponding
insensibility of the electroscope. Thus a signal given by closing
or interrupting an insulated circuit at any point is instantaneously
transmitted from that point in both directions and at full speed ;
but the interval before it attains its total force at any other point

NATURAL PHILOSOPHY. 1G1

must depend upon the character of the intervening conductor.
The question as to the route by which signals are transmitted
when part of the circuit is formed by the earth, is thus disposed
of; and the position maintained in the memoir above cited is
entirely corroborated, although it loses its theoretical significance.

The duration of one signal current was intended to be uni-
formly one-quarter of a second, but depended upon the skill and
care of the observer, no automatic signal-giver having been em-
ployed. Every electrician knows how greatly the strength of the
current is augmented by an increase of its duration from 0.2 s to
0.3 s , yet the duration of the signals varied frequently through a
larger range than this. Still the actual length of each signal as
recorded upon the chronograph register, and its average did not
vary much from the prescribed duration of 0.25 s .

It appears manifest that not an electrical charge or discharge,
but simply anelectrical disturbance, is requisite for transmitting a
signal ; that an inductive impulse, sufficient to deflect the galva-
nometers employed, was transmitted through 1 cable, having at
each end a condenser with 10 cells, in somewhat less than the
third of a second, 5 seconds after the transmission of an impulse
of the opposite sort ; that with a circuit formed by the 2 cables, a
smaller electromotive force sufficed to transmit the signals with
yet greater rapidity ; that the signals travelled more rapidly
through a cable which had not recovered its electrical equilibrium
alter a current of the opposite character; and that the speed of
the signals is modified by the earth connections more rapidly than
by changes in the battery power. And the very marked differ-
ences found in the rates of transmission, between signals given by
completing an interrupted circuit and those given by interrupting
a closed circuit, may perhaps lead to investigations which will
afford an explanation.

CHEMISTEY

ANTOZONE.

IN the first series of Dr. Meissner's researches upon oxygen
lie arrived at the remarkable conclusion that oxygen under the
influence of electrical tension was converted not only into ozone,
but also into another modification, which always appeared
simultaneously, and which formed, when brought into contact
with watery vapor, especially after the absorption of the ozone, a
peculiar dense mist. This second modification of oxygen Meissner
identified with Schb'nbein's antozone. So remarkable were these
results, and so important their bearing, if true, not only upon
our theories of ozone itself, but also upon the philosophy of
chemistry, that Meissner desired to repeat his experiments,
studying particularly the character of the antozone- mist and the
effects of electrical tension upon the volume of the oxygen sub-
mitted to the discharge. The results of these experiments con-
stitute a paper published the last year by Dr. Meissner.*

Oxygen is submitted to the action of electricity in a Siemen's or
Von Babo's apparatus, is then passed into a receiver containing a
concentrated solution of iodide of potassium in which the ozone
is completely absorbed, and finally through water contained in a
second receiver ; the gas, as it issues from the water, forms above
it a thick white mist, which also appears in a less degree over the
solution of iodide of potassium, but which is denser the less con-
centrated the solution and the more favorable the ozonizing
conditions. To prove that this mist consists solely of electrized
oxygen and water, Meissner proves experimentally, to his own
satisfaction : 1st. That no other gas but oxygen is in any way
concerned in the production of the phenomenon, particularly no
nitrogen, chlorine, hydrogen, or carbonic acid; 2d. That for
the production of the result the presence of aqueous vapor in
the electrizing tube is not necessary; 3d. That the solution of
iodide of potassium used for the absorption of the ozone has
nothing whatever to do with the appearance of the phenomenon,
further than is implied in effecting the removal of the ozone from
the current of electrized oxygen.

* Neue Untersuchungen liber den elektrisirten Saticrstoff. Abbaudlungen
dor K. Gosellscbaft der Wissenschaften zu Gottingen, XIV. (ISG'J).

162

CHEMISTRY. 163

In regard to the first and second points, after detailing the very
carefully conducted experiments which were performed, Meissner
believes, " that these experiments, not once only or a few times
repeated, but performed very frequently, prove the following
point : that the mist formed by deozonized electrized oxygen with
aqueous vapor appears when neither chlorine, nitrogen, am-
monia, hydrogen, carbonic acid, nor watery vapor is present in
the tube where the electrizing occurs ; and that tho presence or
aid of neither of these substances is necessary for its subsequent
formation ; that, in other words, the mist phenomenon requires
only dry electrized oxygen, the iodide of potassium used for de-
ozonization and the vapor of water for its production." The third
point is proved by the substitution for the iodide of potassium of
a variety of other bodies, differing widely in chemical character
and agreeing only in the property of absorbing ozone. The mist
is chemically identical whatever be the agent used to absorb the
ozone ; it is neither acid nor alkaline, consists of a body neither
soluble nor insoluble in water, but is solely a mechanical or ad-
hesive combination of oxygen and water, which, when washed
and collected in a gas-holder, gradually disappears, fine fluid
drops collecting upon the walls of the vessel, which, when ex-
amined, are found to be pure water, containing possibly, under
certain conditions, a trace of peroxide of hydrogen. Experiment
leads to the conclusion that there exists in the pure, dry electrized
oxygen, besides unaltered oxygen and ozone, a third body, a
third modification or condition of oxygen, to which the phenome-
non of the mist is to be ascribed. The paper further treats of the
action of various substances on electrized oxygen, and in a second
section discusses the " quantitative estimation of ozone and the
contraction of volume in electrizing oxygen. 11 From an " Abstract
of the second series of Professor Meissner^s Researches upon Electrized
Oxygen? by Prof. Barker in tlie Amer. Jour. Science, L. (1870), pp.
213-223.

HTDROGENIUM-AMALGAM.

" When zinc-amalgam is shaken with water a slow decomposi-
tion of the latter takes place, recognized by the formation of floe-
culi of hydrated oxide of zinc, and the evolution of small bubbles
of hydrogen on allowing the mixture to stand for a time. This
decomposition of water by zinc is intensified when a small
quantity of bichloride of platinum is present; a spongy body then
being formed on the surface of the zinc-amalgam. This body I
have found to be an alloy of hydrogenium and mercury.

" In order to obtain the hydrogenium-amalgam on a larger
scale, zinc-amalgam, containing a few per cent, of zinc, is shaken
thoroughly with about an equal volume of bichloride of platinum,
containing about 10 per cent, of the bichloride, care being taken to
keep the mixture cool. The zinc-amalgam swells up con-
siderably, precisely as in the ammonium-amalgam experiment,
and continues to evolve hydrogen till the decomposition of the
amalgam is complete. I found that the volume of the hy-

1C4 ANNUAL OF SCIENTIFIC DISCOVERY.

drogen thus developed was, in several experiments, from 100 to
150 times that of the mercury employed. This hydrogen pos-
sesses a faint odor.

"When this amalgam of hyclrogeninm is pressed, directly
after its preparation, between sheets of filtering paper, and then
spread out in a layer to the air, the temperature soon rises con-
siderably, and vapors of water are formed, which may be
condensed in a glass receiver. The finely divided platinum
present is obviously the cause of this rapid oxidation of the hy-
drogenium. In this action of bichloride of platinum upon zinc-
amalgam oxychloride of zinc is at the same time formed ; and
though this maybe removed by means of chlorhydric acid, yet by
this treatment a part of the hydrogenium-amalgam is destroyed.
If after this it be washed with water, it undergoes a very slow
decomposition, the volume increases, and bubbles of hydrogen
escape through the water above.

" Platinum, after perfect amalgamation, does not act as en-
ergetically as in its nascent state ; that is, when precipitated on
the amalgam. When platinum-amalgam is mixed with zinc-
amalgam the decomposition of the water by the zinc is extremely
slow, and the hydrogenium-amalgam does not appear for some
time. Under certain conditions, moreover, the hydrogeuium-
amalgam is formed without the aid of the bichloride of platinum.
I had at one time about 20 pounds of mercury containing zinc,
which was left standing in a bottle with water for 3 weeks ; the
hydrogenium-amalgam formed on the surface of the mercury,
gradually decomposing above and being renewed from below."
0. Loew. Annals Lyceum Natural History of New York.

AMMONIUM-AMALGAM.

The existence of ammonium NH4, as such, in what is known as
ammonium-amalgam, has never been demonstrated, although its
constituents escape in proper proportions from the amalgam. If
the hydrogen escaping from the amalgam, together with the
ammonia (NHs), be shown to be in the nascent state, it would be
evidence that it had just been in chemical combination with the
ammonia; in other words, that metallic ammonium existed in the
amalgam. Some pellets of sodium were placed in contact with
some particles of the transparent variety of phosphorus, wrapped
in bibulous paper and plunged beneath the surface of water. A
red glow was seen ; and as the nascent hydrogen came in contact
with the phosphorus, bubbles of phosphide of hydrogen were
formed. Occasionally one would inflame as it came into contact
with the atmosphere, placing the nature of the reaction beyond
a doubt. As phosphide of hydrogen cannot be formed by direct
synthesis if ordinary free hydrogen be employed, this becomes a
test for the presence of that gas in its nascent state. The hydro-
gen escaping from the ammoniacal amalgam was now tested by
this process. A sodium-amalgam, dipped beneath a solution of
chloride of ammonium, was employed ; and it became necessary

CHEMISTRY. 165

to wait until the sodium was exhausted that results might not be
vitiated by the nascent hydrogen escaping from the water. At
the proper time the decomposing amalgam was covered with
fragments of transparent phosphorus, when many bubbles of in-
flammable phosphide were obtained. The hydrogen must then
have been in the nascent state and just escaping from the am-
mojiium. Dr. Gallatin, in the Philosophical Magazine, July, 1869,
p. 57.

ACTION OF LIGHT ON CRYSTALLIZED SULPHUR.

We know, from the researches of Schroetter on the allotropic
modifications of phosphorus, that ordinary phosphorus is con-
verted by the action of light into the amorphous variety. M. Lalle-
mand finds that a similar effect is produced on ordinary crystallized
sulphur. He exposed a solution of sulphur in bisulphide of car-
bon, in a sealed glass vessel, to rays of light concentrated by u
lens, and obtained a copious deposit of amorphous sulphur. On
passing the emerging rays through a prism, he found that the
luminous spectrum showed no rays between G and H, and that
the ultra-violet rays had disappeared entirely. A solution of
phosphorus in bisulphide of carbon acts similarly, although more
slowly, and the spectrum produced by the emerging light shows
a sensible diminution of intensity only in the neighborhood of H
in the luminous spectrum, and only the most refrangible actinic
rays have disappeared. Comptes Rendus, LXX., p. 182.

SOLUBILITY OF SULPHATE OF LEAD IN ALCOHOLIC SALINE

SOLUTIONS.

Very considerable quantities of sulphate of lead can be held
dissolved in ivater by means of many acetates, citrates, tartrates,
and by various 'other salts. Prof. Storer finds that a certain pro-
portion of lead can be held dissolved in presence of sulphuric acid,
even in an alcoholic solution like wine, by the action of various
soluble alkaline salts capable of decomposing and of being de-
composed by sulphate of lead. Attention was called to the fact by
the analysis of a sample of sherry, which proved to contain some
salt of lead, and, at the same time, free sulphuric acid. Among
the salts which possess in dilute alcoholic solutions this power of
holding lead dissolved, are the acetate, tartrate, succinale, citrate,
and dicitrate of ammonium, and tricitrate of potassium. The ex-
periments made show clearly that very considerable quantities of
sulphate of lead can be held in solution by weak alcohol charged
with various salts. It may, therefore, reasonably be inferred
that wines sometimes retain lead in solution, in consequence of
this action of the acids and salts peculiar to wine upon lead com-
pounds ignorantly employed to correct acidity. Proc. Amer.
Acad., x.,^?. 59.

16G ANNUAL OP SCIENTIFIC DISCOVERY.

JARGONIUM.

In the last volume of this Annual, a statement was made of
the fact that Mr. Sorby, in the course of an examination of the
absorption-spectra given by zirconia and other earths, found that
certain specimens of jargon from Ceylon yielded a spectrum of so
marked a character as to lead to the supposition of the existence
of a new element, to which he gave the name of jargonium. Up-
on analyzing the jargon a quantity of substance was obtained
which, while resembling zirconia, was sufficiently distinct from it
to warrant the supposition of its being the oxide of a new metal.
At the same time the element uranium failed to reveal itself in
the course of ordinary or spectral analysis. In February of the
last % year Mr. Sorby read a paper before the Royal Society * de-
scribing more recent experiments, which show that the absorption-
bands which seemed to indicate the presence of a new element
are really due to a mixture of the oxides of zirconium and ura-
nium, and this reaction is so delicate as to give evidence of the
presence of uranium when the amount is extremely small. He
found that, in the case of transparent blowpipe beads of borax
with microcosmic salt, it is requisite to have about as much as
one-fiftieth grain of protoxide of uranium to show faintly the
characteristic absorption-bands; whereas when present along
with zirconia in crystalline beads, one-fifty-thousandth grain gives
an equally well-marked spectrum, and one-two-thousandth grain
shows it far better than a larger quantity, which makes the bead
too opaque.

MANUFACTURE OF CHLORINE.

Wddorfs Process. In the last volume of the " Annual of Scien-
tific Discovery " mention was made of the process invented by
Walter Weklon, for the utilization of the chloride of manganese
residues from the chlorine manufacture by the production from
the same of a compound which he calls manganite of calcium,
which is used again to generate chlorine. This process has been
extensively adopted in England within the last year or two, and
at the meeting of the British Association at Liverpool, 1870, the
inventor of the process read a paper, f giving further details, and
at the same time he exhibited a model of the apparatus employed.

The following is an abstract of this paper: The vessels com-
prised in this apparatus are arranged at 5 successive elevations,
so that after having been pumped up to the highest of them the
liquor operated upon can afterwards descend to all the others by
its own gravity. The lowest of these vessels is a well, which is
furnished with a mechanical agitator. The slightly acid chloride
of manganese liquor with which the process commences runs from
the stilTs in which it is produced into this well, and is there
treated with finely divided carbonate of calcium, the action of which

* Chcrn. News, xxi., p. 73, American Preprint, vi., p. 193.

f Printed in the "Ckem. News" for Sept. 23, 1870, Vol. xxii., p. 145.

CHEMISTRY. 167

is facilitated by energetic agitation. When the neutralization of
the free acid which is at first contained in this liquor, and the
decomposition of the sesquichloride of iron and sesquichloride of
aluminum, which are also at first contained in it, are completed,
the liquor is pumped up into settling-tanks placed nearly at the
top of the apparatus and known as the chloride of manganese
settlers. It now consists of a quite neutral mixed solution of
chloride of manganese and chloride of calcium, containing in
suspension considerable quantities of sulphate of calcium and small
quantities of oxide of iron and alumina. These solid matters
rapidly deposit in the chloride of manganese settlers, leaving the
bulk of the liquor perfectly bright and clear and of a faint rose-
color. The next step is to run off the clear portion of the con-
tents of the chloride of manganese settlers into a vessel placed
immediately below those settlers, and called the oxidizer. This
is usuall}' a cylindrical iron vessel, about 12 feet in diameter and
about 22 feet deep. Two pipes go down nearly to the bottom of
the oxidizer, a large one for conveying a blast of air from a
blowing-engine, and a smaller one for the injection of steam.
The latter is for the purpose of raising the temperature of the
contents of the oxidizer, when necessary, for sometimes the
chloride of manganese liquor reaches the oxidizer sufficiently
hot, to somewhere between 130 and 160 or 170 F. Immedi-
ately above the oxidizer is a reservoir containing milk of lime.
The oxidizer having received a charge of clear liquor from the
chloride of manganese settlers, and this liquor having been heated
up to the proper point, if it was not already hot enough, blowing is
begun, and milk of lime is then run into the oxidizer as rapidly
as possible, until the filtrate from a sample taken at a tap placed
nearly at the bottom of the oxidizer ceases to give a manganese
reaction with solution of bleaching-powder. A certain further
quantity of milk of lime is then added, and the blowing is
continued until peroxidation ceases to advance. That point is
usually attained when from about 80 to 85 per cent, of the man-
ganese present has been converted into peroxide. The contents
of the oxidizer are now a thin black mud, consisting of solution
of chloride of calcium containing in suspension about 2 pounds of
peroxide of manganese per cubic foot, these two pounds of per-
oxide of manganese being combined with varying quantities of
protoxide of manganese and lime. This thin mud is now run
off from the oxidizer into one of a range of settling tanks
(mud-settlers} placed below it, and is there left at rest until about
one-half of its volume has become clear. The clear part, con-
sisting simply of a solution of chloride of calcium, is then decanted,
and the remainder, containing about 4 pounds of peroxide of
manganese per cubic foot, is then ready to be used in the stills.
There it reacts upon chlorhydric acid, liberating chlorine, with
reproduction of exactly such a residual solution as was com-
menced with. With that solution the round of operations is
begun again ; and so on, time after time, indefinitely.

In regard to the amount of lime necessary : The lime
used is slaked with as nearly as possible an equivalent of water

1CS ANNUAL OF SCIENTIFIC DISCOVERY.

and passed through fine sieves. Including the portion which is
sieved out, and which, although it does not go into the oxidizer,
is usually charged to the process, the amount of lime used at
present averages 14 cwt. per ton of bleaching-powder prepared.
Until quite recently it was supposed that whatever proportion of
lime was used in the oxidizer, products could not be obtained con-
taining less than an equivalent of base (or bases) to every equiv-
alent of peroxide of manganese. Now, however, products are
regularly obtained containing only between 0.9 and 0.7 equivalent
of base, and there have been obtained, occasionally, compounds
containing as little as 0.5 equivalent of base ; in case of producing
regularly compounds containing only one-half an equivalent of
base, the amount of lime required for this purpose may be reduced
as low as 10 cwt. per ton of bleaching-powder, and already, at
one work on the T}*ne, the amount has been reduced to 12 cwt.

The mechanical power expended in the injection of the neces-
sary amount of air into the oxidizer has hitherto averaged between
7 and 8 Gorge-power for 1 hour per 100 pounds MnO2 made ; but
this amount can probably be diminished. Expressed in terms
of the amount of bleaching-powder produced, it may be said that
the production of 1 ton of bleaching-powder requires the expendi-
ture of from 35 to 40 horse-power for 2 hours.

The quantity of acid consumed per ton of bleaching-powder
made by means of mangauite mud, varies with the degree of care
with which the process is performed and with the general skill of the
manufacturer, being in some cases considerably below the average
quantity consumed in making a ton of bleaching-powder by means
of native manganese, while in other cases it is scarcely at all below
that quantity. To produce a ton of bleaching-powder by the ordi-
nary process there is required the amount of acid obtained from
not less than GO cwt. of salt, and often there is used as much acid
as would be produced from 80 cwt. of salt. By the new process
at least one manufacturer, whose mud contains as yet by no
means the minimum amount of base, consumes to the ton of
bleaching-powder only 170 cubic feet of acid at 24 Twaddell, a
quantity which may be produced by less than 48 cwt. of salt.

The loss of manganese which occurs in this process at present
varies from about 4 per cent, to about 10 per cent. The deposit of
sulphate of calcium and other matters in the chloride of manganese
settlers has to be removed as a thin mud, that is, mixed with a
quantity of the solution of chloride of manganese. By suitable
washing the amount of manganese lost may be reduced to 2 per
cent., but it ordinarily averages 5 per cent. No other sources pf
loss exist, except it be from carelessness on the part of the work-
men. Beyond the sulphate of lime and other bodies which are
deposited in the chloride of manganese settlers, the only residual
product of the process, and the only other thing which has to be
thrown away, is the solution of chloride of calcium. As this- so-
lution represents all the lime and all the limestone used
in the process, and two-thirds of the chlorine contained in
the acid employed, attempts have been made still farther to im-
prove the process by the substitution of magnesia in the place of

CHEMISTRY. 169

lime, and by decomposing by heat the resulting chloride of mag-
nesium into magnesia, for use over again, and chlorhydric acid.
In this form, the process is capable of yielding all the chlorine
contained in the acid employed, and apart from mechanical loss
employs no materials except coal and air, which are not used over
and over again. Experiments on a small scale promise well for
the value of this modified process.

Deacon's Process. If a mixture of chlorhydric acid and oxygen
be sufficiently heated, portions of the hydrogen and oxygen com-
bine, and chlorine is set free to a certain small amount. This
proportion is very much increased by passing a heated mixture
of these gases over certain substances which influence this reac-
tion without being themselves, as far as appears, affected by it.
Copper salts possess the power of bringing about this reaction in
a very marked degree, sulphate of copper being most conven-
iently employed. All the compounds of lead, with the excep-
tion of the sulphate, act in the same way, although requiring a
higher temperature. All the manganese compounds act simi-
larly, but the temperature required is so elevated that all the
liberated chlorine is not obtained as such, a certain amount appar-
ently recombining with a portion of the hydrogen of the water
formed.

It is proposed to make use of these facts in the commercial pro-
duction of chlorine, by passing the mixed gases over common
bricks soaked in a saturated solution of sulphate of copper, and
then dried. It has been found that the chlorhydric acid, as
evolved from the ordinary salt-cake apparatus, contains, mixed
with it, a sufficient quantity of air for the reaction to take place.
It has been found that iron resists very completely the action of
chlorine in the decomposing apparatus. A common iron gas-
pipe, exposed to the heated chlorine for several months, shows
no appreciable wear. The chlorine produced is mixed with a
large proportion of nitrogen, but no difficulty is anticipated in the
making of bleaching-powder, if the saturation is brought about
systematically by allowing the strong gases to meet lime nearly
saturated, and then passing the weaker gases over fresh lime.
Any undecomposed chlorhydric acid is removed by passing the
gases through water, the dilute acid formed dissolving only mere
traces of chlorine. Abstract of a paper read before the British
Association, 1870, by Henry Deacon.

Hargreaves 1 Process. Mr. James Hargreave, of Witlness, has
devised a method for producing chlorine without the use of ox-
ide of manganese. He has a process for the separation of phos-
phorus from the iron slag produced in the puddling operation of
the iron manufacture. In carrying out this process the iron slag
is treated with chlorhydric acid, and thereby protochloride of
iron in solution is obtained as a by-product. This solution is
evaporated to dryness, and the dry protochloride, by slow appli-
cation of heat with access of atmospheric air, becomes perchloride,
which undergoes decomposition, yielding chlorine and peroxide of
iron. This process yields an equivalent of chlorine for each equiv-
alent of chlorhydric acid employed.

170 ANNUAL OF SCIENTIFIC DISCOVERY.

ALKALI MANUFACTURE IN GREAT BRITAIN.

In 1861, it was estimated that the total quantity of salt decora-
posed in Great Britain, for the production of soda, was 260,000
tons. According to the returns of the Alkali Manufacturers' As-
sociation for the year 1869, the total quantity decomposed was
326,000 tons, showing an increase of 25 per cent.

CLAUDET'S PROCESS FOR THE EXTRACTION OF SILVER.

The amount of pyrites annually burned in Great Britain in the
manufacture of sulphuric acid reaches 350,000 tons, of which at
least 250,000 tons contain a sufficient amount of copper to render its
treatment for that metal commercially advantageous. For several
years past a large proportion of the " burnt ore " produced in the
various chemical works of the country has been worked by what
is known as the ivet process of extraction. By the process of liquid
extraction at present usually employed, the burnt ore is first
finely ground and sifted, and subsequently roasted with common
salt until by the oxidation of the metallic sulphides present a
portion of the alkaline salt is converted into sulphate of sodium,
whilst the copper is, on the contrary, converted into a soluble
chloride. The copper salt is subsequently removed by repeated
washings and the copper precipitated by iron in the metallic
state.

This precipitated copper contains a notable quantity of silver
as well as a distinct trace of gold. Thus in 9 successive wash-
ings of one tank of ore there were found respectively 4.06, 3.25,
1.05, 0.19, 0.12, 0.06, 0.03, 0.06, 0.04 grains of silverto the gallon
of liquor. This silver comes from the ore which has been roasted
with common salt as chloride held in solution by the large amount
of undecomposed chloride of sodium. Of these various washings
the first 3 alone contain enough of the precious metal to pay
for working. The treatment is as follows :

These liquors are first run into suitable wooden cisterns, each
of a capacity of about 2,700 gallons, where they are allowed to
settle. The yield of silver per gallon is now ascertained by tak-
ing a measured quantity, to which are added chlorhj^dric acid,
iodide of potassium, and acetate of lead in solution. The precip-
itate obtained is thrown upon a filter, and after being dried is
fused with a flux, consisting of a mixture of carbonate of so-
dium, borax, and lamp-black. The resulting argentiferous lead is
passed to the cupel, and from the weight of the button of silver
obtained the amount of that metal in a gallon of the liquor is
estimated.

The liquor from the settling-vat is now allowed to flow into
another of slightly larger capacity, whilst at the same time the
exact amount of a soluble iodide necessary to precipitate the sil-
ver present is run into it from a graduated tank, together with a
quantity of water equal to about one-tenth the volume of the
copper liquor. During the filling of the second tank, its con-

CHEMISTRY. 171

tents are continually stirred, and when filled a little lime-water
is added, and the mixture is allowed to settle during 48 hours.

The precipitate formed is chiefly composed of sulphate of lead,
iodide of silver, and salts of copper, which latter are readily re-
moved by washing with water acidulated with chlorhydric acid.
The precipitate is then decomposed by metallic zinc, which re-
duces completely the iodide of silver, and to a certain extent the
sulphate of lead. There result (1) a solution of iodide of zinc,
which after being standardized is employed in subsequent opera-
tions to precipitate fresh quantities of silver; (2) a precipitate
containing about 4.5 per cent, of silver, 0.06 percent, of gold,
15.5 per cent, of zinc, and 56.5 per cent, of copper.

The result of nearly 6 months' experience of this process, at the
Widnes Metal Works, shows that one-half ounce of silver and 1
grain gold may be extracted from each ton of ore worked at a
total cost of Sd. per ton. A profit of 2s. per ton is thus obtained,
an amount not to be disregarded in works which treat 30,000
tons of ore annually. Abstract of a paper read by J. Arthur
Phillips before the British Association, 1870.

GAS MANUFACTURE.

Neiv Process of Gas Manufacture. In this process, which is
patented, and which is at present in operation under the auspices
of the Citizens' Gas Light Company, Saratoga, N. Y., the gas is
made from crude naphtha in an essentially " new" method.

The naphtha is put into a still and gradually converted into
vapor by a steam coil. The vapor is thence conducted into a
peculiarly constructed superheater, placed inside a clay or iron
retort, set and heated in the usual way. There is in use
here one bench of 3, each retort provided with a super-
heater. The vapor enters the rear of the retorts from the
superheater, where it is instantly converted into a fixed gas,
and passes into the stand-pipes, and so on to the gas-holder
in the usual way, except that no washing, scrubbing, or puri-
fication is needed, a simple tank and condensing' coil being all
that is required.

One bench of 3 will produce 5,000 feet of gas per hour, pre-
pared for distribution, of not less than 20 candle-power, equal
to 120,000 cubic feet per day of 24 hours. One bench of 5 will
easily produce 200,000 cubic feet per day. The expense of labor
is reduced to a minimum ; only an engineer and one fireman
being necessary. The entire process is so nearly automatic that
but little manual labor is required. There is no charging and
discharging of retorts, no troublesome stoppage of stand-pipes,
or scaling and decarbonizing of retorts, no laborious and disagree-
able purifying process. There are no bad odors, smoke, or soot.
The first cost of works, it will be readily understood, is much less;
scrubbers, washers, and purifiers being dispensed with, and only
one-tenth the number of benches being required to produce a
given amount of gas, and, owing to the low heats employed, the

172 ANNUAL OF SCIENTIFIC DISCOVERY.

wear and tear is far less. Another remarkable feature of this gas
is its non-condensability in the mains, none of the drips having
yet required to be pumped. The loss by leakage and condensi-
bility is therefore exceedingly small, never having exceeded 3
per cent. The mains in one place, particularly, are laid only 16
inches under the surface for a space of one-half mile, owing to
the difficulty of excavating a very hard unstratified rock. But
during last winter, with the thermometer often at and below zero,
no trouble of condensation was experienced.

Other materials can be used beside naphtha, any of the prod-
ucts of the oil-wells, such as crude petroleum, dead oil, "still
foots," etc. Any oil or oily or fatty matter may be used. In fact,
all liquid, semi-liquid, or solid carbonaceous matter can be em-
ployed to make gas by this process ; and the letters patent ful-
ly specify and cover this ground. It is only necessary to ob-
serve that, where the materials used do not vaporize (like naph-
tha, etc.,) by the application of a steam coil, it is only necessary
to apply a sufficient degree of heat through the aid of a furnace,
that will convert the material into a vapor, in the first instance;
and that this vapor (which is necessarily more or less condensable)
shall pass into a retort heated to a temperature sufficient to con-
vert it all into a fixed gas. This is the great novelty of the inven-
tion, and gives it the great advantage over the ordinary method
of distilling either oils and other hydro-carbons, or coals and the
like materials, to produce illuminating gas. If coal is used, it
first distils, and oil as a condensable vapor is eliminated ; this,
instead of going to make coal tar in the hydraulic main as usual,
is passed into a red-hot retort, where it becomes a true gas, and
nothing else.

This process is a great stride in the art of making gas upon
true chemical principles. In the old process, the charge of coal
is thrown into a hot retort ; a portion next the retort is distilled
at a proper temperature to produce a fixed gas ; but another
portion in the centre of the charge is distilled at a low tempera-
ture, which will only yield oily and condensable matter, and this
goes to form the tar in the hydraulic main. This is the very
essence, so to speak, of gas, and is a dead loss to the process in a
chemical sense. Again, another portion of the charge becomes
too highly heated, and is destructively decomposed, forming
either a hard incrustation on the sides of the retorts called gas
carbon, or clogs the mouth-piece and stand and bridge pipes, in
the form of a combined gummy and sooty matter. Although the
gas may be formed properly in one part of the retort, before it
escapes a portion becomes decomposed and resolved into new
chemical combinations, principally carbonic oxide, carbonic acid
gas, and free hydrogen. All this is wrong, and to the analytical
mind of the scientist, but more especially to the practical mind
that comprehends it fully, the whole process of gas-making ap-
pears not only absurd but even ridiculous, when compared with
the new process. Amer. Oas-Liglit Jour.

The McCracken Process. By this process of gas manufacture
the tar condensing in the hydraulic main is allowed to overflow,

CHEMISTRY. 173

and, being conducted in a fine stream to the rear end of the re-
torts, enters in company with a certain amount of water
which, when it reaches the retorts, is in the state of superheated
steam. There results from the tar and the superheated steam a
mixture of hydrocarbons and carbonic oxide, which go forward to
increase the amount of gas. Retorts of a peculiar construction
are employed.

Enrichment of Gas. In view of the difficulty of obtaining bog-
head cannel and other coals suitable for the enrichment of gas,
considerable use is being made of bitumen from the Island of
Trinidad, where there exists a supply practically inexhaustible.
This bitumen is used by the Brooklyn (N. Y.) Gas Company and
gives full satisfaction. Amer. Oas-Liglit Jour.

Use of Sulphuric Acid in Coal-Gas Purification. Mr. M. C.
Pelonze publishes an article in the "Journal of Gas Lighting," on
the use of sulphuric acid for the removal of ammonia from coal-
gas, and states that, heretofore, the sulphuric acid was improperly
applied, either diluted in scrubbers or more concentrated in
purifying-boxes. In both cases the gas takes up some of the acid,
and thus deteriorates the pipes and burners. Pelouze besprinkles
his purifying material (oxide of iron or sawdust) with water con-
taining 20 per cent, sulphuric acid of 53B. (spec. gray. 1.53).
The material is then exposed to the air in a warm place until
sufficiently dried, and is then used. After use sulphuric acid must
be added to replace that which was neutralized by the ammonia.
When the salt of sulphate of ammonium has accumulated it may
be washed out with water, and the solution worked up. Pelouze
states that this method also prevents the separation of naphtha-
line. Amer. Chemist .

Reagent for Detecting Ammonia in Illuminating Gas. M. Meu-
nier prepares a tincture of the fresh leaves of the Colcus Ver-
sclwftelti by treating these leaves with absolute alcohol to which a
fe\v drops of sulphuric acid have been added. Slips of Swedish
filter-paper dyed with this tincture and dried in the open air
furnish a valuable test for the presence of ammonia, being turned
green by alkalies. The presence of ammonia in coal gas may be
ascertained by holding one of the moistened strips for a *few
moments in a current of the gas. The paper should be preserved
in well-stoppered bottles. Cosmos.

Determination of Sulphur in Coal Gas. Vernon Harcourt's
method is as follows: "In my apparatus I use a small Bun-
sen burner, which gives a flame, scarcely visible in the daj'light,
of three-quarters of an inch in length, when burning at the rate of
a quarter of a cubic foot per hour. The gas is supplied by
means of an aspirator with between 20 and 30 times its volume
of air. A funnel placed at the top of the cylinder in which the
gas burns admits the air through holes in the neck, and dis-
tributes it down the sides of the cylinder, while the products of
combustion and the excess of heated air are withdrawn from
within the funnel through a tube rising from the bottom of the
cylinder. This tube fits loosely into another tube, which passes
through an India-rubber plug closing the cylinder, and is attached

174 ANNUAL OF SCIENTIFIC DISCOVERY.

to a system of bulbs, through which are driven the air in which
the gas has burned and the liquid used to wash it. From the
bulbs they pass into a two-necked receiver placed over the cylin-
der, whence the air escapes into the aspirator, while the liquid de-
scends through a small tube to the bottom of the cylinder and
repeats its course. The liquid used is an ammoniacal solution of
copper, the ammonia serving to fix the sulphur compounds,
while the copper determines, in presence of an excess of air, the
oxidation of sulphite to sulphate." The air which enters the ap-
paratus is freed from sulphur compounds by being passed through
an ammoniacal solution of copper. When about 2 cubic feet
of gas have been consumed the liquor is drawn off, the apparatus
rinsed with water, and the sulphur precipitated as sulphate of
barium after the excess of ammonia has been driven off. Lond.
Jour, of Gas-Lighting.

Various Formulce proposed for the Relation between the Quantity
of Light produced and the Amount of Gas consumed. Fred. E.
Stimpson. The author found upon examination that three for-
muloe had been proposed for this reduction, namely :

(1) The common one

1 L
V 0"

which is expressed by saying that the quantity of light, Z, is pro-
portional to the quantity of gas, g, consumed ; (2) that produced
and used by Bunsen and Roscoe, Phil. Trans., CXLIX. (1859),
page 884,

I I' g g'

V^T" ~ </-</"

which is expressed by saying that for a given burner the increase
of light is proportional to the increase of the quantity of gas con-
sumed ; (3) "Farmer's Formula," proposed by Professor Silli-
man at the Salem Meeting of the American Association,

L= ^

V ' g>*

which is expressed by saying that the light is proportional to the
square of the consumption. These three formulas, transposed
so as to express the value of I, become,

V
! l ~ ~ or l

(3.) I = - or I = Ag*.
y

Mr. Stimpson had collected from various publications upwards
of 120 independent series of determinations of the relative illu-
minating power of gas consumed at various rates from different
burners. These burners comprised single jet, union jet, or
fish-tail, slit or bat's-wing, and argand ; each set contained from 2
to 10 single determinations. These series, together with some of

CHEMISTRY. 1 7i)

his own determinations, were represented in the form of curves,
and by means of the magnesium lantern projected on to a screen
for inspection. From the results of observations thus far made,
he concluded that Bunsen's and Roscoe's formula (a straight line
cutting the axis <?) would represent the greatest number of series,
and particularly the series belonging to the argand burners.

That for those series belonging to the jet, the fish-tail and bat's-
wing burners, the common formula (a straight line passing
through the origin), which is a modification of Bunsen's, in which
B zzz O, very closely represents the relation found by experiment.
The number of cases in which the series or any considerable part
of the series could be represented by formula 3 (a parabola) were
very few. Mr. Stirnpson found, however, that when a gas flame
was on the verge of the smoky condition, a tangent to the curve
would almost always pass through the origin, showing that
for a limited range of consumption at that point the light is
proportional to the consumption. One other point was also very
apparent; such is the influence of the burner upon the flame, that,
in order to get the best result for any given consumption, the
burner must be of the kind best fitted for that particular con-
sumption. Amer. Gas-Light Jour, from Proc. Amer. Association.

Farmer's Theorem. Many of Professor Silliman's experiments,
on which he relied to establish "Farmer's Theorem, 1 ' were per-
formed by mixing a very rich gas, which could not be burned in
a 15-hole argand-burner at the rate of 5 feet an hour, with a poor
gas of known power. Mr. Stimpson objects to this " method of
mixtures." Processor Silliman subsequently performed a limited
number of experiments by mixing a gas of known power with
hydrogen, and determining the candle-power of the mixture. He
finds the results sufficiently in accordance with theory to justify him
in asserting the applicability of the following rule : To find the
candle-power of a gas having, for example, an intensity greater
than 20 candles, mix the rich gas of unknown power with a
poorer gas of known power in such proportions that the intensity
of the mixture shall not be greater than 20 candle-power when
consumed at the agreed rate of not over 5 cubic feet per hour.
Then, to compute the candle-power of the rich gas, subtract the
intensity (6) of the poor gas from the intensity (cZ) of the mix-
ture ; multiply the remainder by the volume (a) of the poor gas ;
divide the product by the volume (c) of the rich gas ; add to the
quotient the intensity (d) of the mixed gas, and the sum is the in-
tensity (x) of the rich gas sought. That is, since

ab -4~ ex (d 6) a

= a, then x \- d.

a-\- c c

Amer. Jour. Science.

Influence exerted on the Illuminating Power of Gas by the Pres-
ence of Carbonic Acid. That the presence of carbonic acid in
illuminating gas should exert some influence on its illuminating
power, it would be very natural to suppose. Owing to the (until
recently) general use of lime for the purification of gas, no careful
and direct experiments on the subject have been published. The use
of oxide of iron in the place of lime, and the consequent retaining by

176 ANNUAL OF SCIENTIFIC DISCOVERY.

the gas of the carbonic acid to a certain extent, render experiments
on the subject desirable. Such experiments were made in the
year 1863 by Prof. W. B. Rogers, assisted by Mr. Fred. E. Stirap-
son, present Inspector of gas and gas-meters for the State of Mas-
sachusetts. The experiments were performed by mixing ordinary
Boston illuminating gas (containing about 2.5 per cent, of car-
bonic acid on the average) with different quantities of carbonic
acid, and burning first the ordinary gas and then the mixture in
the same 15-hole argand burner, the gas in both cases being passed
at the same rate (5 feet per hour) through the same dry meter. It
was found that the gas for every additional per cent, of carbonic
acid lost 6 percent, of its illuminating power up to a certain point,
and that further addition of carbonic acid caused further decrease,
but in a smaller ratio. All light was destroyed by the addition
of 58 per cent, of carbonic acid. Fred. E. Stimpson, at the Troy
Meeting of American Association.

The non-luminosity of the Bunsen flame is not due, according to
Knapp, to the fact that the mixture of air and gas affords a more
complete combustion of the latter. He finds that chlorhydric
acid, carbonic acid, or even pure nitrogen, causes the same effect,
and therefore believes that the loss of light is due partly to the
cooling of the flame, but mainly to the dilution of the gas. Journ.
fur prakt. Chemie.

CONDITION OF CARBON AND SILICON IN IRON AND STEEL.

At a meeting of the Iron and Steel Institute held at Merthyr
Ty civil, in South Wales, in September of the last year (1870), Mr.
G. J. Snelus read a paper with the above title. This paper con-
tained the results of a long course of experimental inquiry, in-
stituted with a view to determine the conditions in which the two
non-metallic bodies, carbon and silicon, exist in iron and steel.
Dr. Perry had said, in his celebrated work on "Iron and Steel,"
that not a trace of graphite could be detached by the point
of a pen-knife from the fractured surface of highly graphitic
iron ; but Mr. Snelus had proved the incorrectness of this state-
ment by examining some pig iron which had cooled slowly under
a mass of slag, and which had in consequence very large crystals.
From the surfaces of these crystals the graphite could not only
be separated with the point of a pen-knife, but even with the
finger-nail ; and when the graphite was removed the iron under-
neath rusted rapidly in a damp atmosphere.

By pulverizing pig iron and then using the magnet, a consider-
able amount of graphite was separated. In spiegelcisen the
carbon was found to be almost wholly combined. The author
had never found as much as 5 per cent, of combined carbon in
pig iron, although many analyses had been published in which
the carbon was put down at even 6 per cent. According to Mr.
Snelus there is no pig iron that is destitute of silicon, and he had
never met with a case in which either steel or wrought iron was
totally free from it. Good Bessemer and tool steel rarely con-

CHEMISTRY. 177

tains more than 2 or 3 parts in 10,000. One part of silicon
in 1,000 of Bessemer metal, renders it hard and brittle when cold.
In ordinary Bessemer pig iron, it is present in quantities varying
from 1 to 4 per cent. The author gave it as his opinion, from ex-
perimental inquiries, that silicon is dissolved or "occluded" in
iron in the same way that carbon is, but that the solvent power
of the metal is so much greater for silicon than for carbon that it
is quite a rare thing, even if it ever occurs, for silicon to separate
in a free state from the iron. Mr. Bessemer confirmed the re-
marks of Mr. Snelus as to the universal presence of silicon even
in the best Sheffield steel ; and alluding to the prevailing opinion
that the presence of silicon was injurious, stated as his opinion
that, on the contrary, the presence of a small quantity of silicon
was beneficial. Eeported in Nature, Sept. 15, 1870.

THE CHEMISTRY OF THE BESSEMER PROCESS.

At the Troy Meeting of the American Association for the Ad-
vancement of Science, Lieut. C. E. Button, U. S. A., read a paper
on this subject, of which the following is an abstract :

" Cast iron the raw material from which the malleable metal
is made may be formulated approximately as follows :

Silicon (Si), 5 to 3 per cent.

Phosphorus (P), 05 to 2 per cent.

Manganese (Mn) , to 20 per cent.

Sulphur (S), 25 to 2 per cent.

Carbon (C), 2 to 5 per cent.

Iron (Fe), - 90 to 96.5 percent.

*' It is a rare thing if pig iron do not contain every one of these
elements, excepting manganese, in proportions within the limits
here given. Although manganese is oftener absent than present,
yet its importance is so great in the metallurgy of iron, that I
have deemed it necessary to introduce it into the discussion, par-
ticulary as its importance is greatest of all in the Bessemer pro-
cess. The percentages given are neither the highest nor the
lowest, but may be considered as the extremes of the normal
varieties. Some few extraordinary brands have been known to
exhibit very remarkable constitutions, such as 8 per cent, of
carbon, and 12 to 15 per cent, of silicon; but these are
mere curiosities of metallurgy, and not useful or practicable
materials."

All these elements are readily oxidized, and, accordingto Lieut.
Button, in the order in which they have been mentioned, the car-
bon being the last impurity to be burned out. After reviewing
the ordinary methods of converting cast iron into wrought iron and
the order and manner of the elimination of the various injurious
substances, Lieut. Button says :

" There is not a substance employed, nor a combination induced
or resolved, in the Bessemer process, which has not been re-

178 ANNUAL OF SCIENTIFIC DISCOVERT.

peatedly made use of for more than 30 years in the commonest
practice of Europe and America. The differences, which are
many and great, are all mechanical, and the Bessemer process
may, with strict accuracy, be said to be the employment of entirely
new mechanical methods and appliances for eff