besides being in close proximity to several acres of flat land suitable for two of the largest sized furnaces which it is in contemplation to erect. The minerals underlie the upper oolite. On the East Riding side of the valley the seam is one of 12ft. thickness, in four or five well-defined blocks; and, taking the average thickness at 9ft., the estimated yield per acre is 30,000 tons, or a supply sufficient to feed two of the largest furnaces for a period of about eighty years. I this locality, too, ironstone abounds, cropping out here and there, and can be worked at a low rate. On the other side of the valley, the estimate of the yield cannot be so exactly determined, nor is the deposition of the minerals so highly favourable for easy working, although by no means difficult. There are also a capital seam of limestone 15ft. thick, now in working, and seams of excellent brick clay, hydraulic limestone, and white sand suitable for moulding, with an abundance of building stone. The ironstone is 14ft. in thickness, and identical with the East Riding deposit. An analysis has been made of the mineral by Mr. Pattison, F.C.S., of Newcastle-upon-Tyne, and assays by two practical mineralogists, and the three reports vary but 2 per cent., giving a mean of 32.00 per cent. of pig-iron. The purity is such that the iron is reported as suited for the Bessemer process. The iron slag for roadmaking will be available at one-half the cost now paid for it in Cleveland by a very large area of the county of York. To the North-Eastern Railway Company, and to the adjoining town of Malton, the development of these mines will be a source of considerable traffic and benefit.

THE

SOCIETY OF ENGINEERS.

HE President, Vice-President, Council, and members of the Society of Engineers returned from their trip to the Paris Exhibition on Friday last. They were enabled, by the courtesy of M. Eugene Flachat, President of the Society of Civil Engineers of France, to inspect the various large manufactories as well as the great public works now being carried out in Paris. The Society's dinner took place at the Trois Frères Provencaux, the president, Mr. w. H. Le Feuvre, occupying the chair. A dinner was also given in the Exhibition by the members of the Railway Congress assembled at Paris, when the chair was occupied by M. Eugene Flachat. The chairman, in the course of his remarks, made special reference to the Society of Engineers, stating that their transactions were held in much regard by continental engineers, on account of the ready publicity given to the views of the authors of the various papers, which unfortunately was not the case abroad. M. Le Feuvre replied on behalf of the Society of Engi. neers. The meeting was altogether of a very agreeable character, and it is to be hoped may not be the last of such meetings between the French and English representatives of the profession.

man more into play, and thereby reducing
manual work. By economising the strength of man
in the reduction of manual labour, a level of
equality is attained in the power of production.
The weak man may produce as much as the
strong man, a woman as much as a man, the
homestead as much as the workman's shop, and
the workman's shop as much as the great
factory.

other. Thus a happy relationship has arisen amongst us. There is scarcely a great workshop or manufactory where the members of our so. ciety are not welcomed and instructed by a fellow workman; and it is this result which leads me now to express in the name of all the members who constitute our society, our gratitude to the English societies who give us so hearty a welcome whenever we visit their industrial establishments. For many years that kind reception given to all who have sought it has engendered a feeling of mutual good-will, which the Exhibition will tend to strengthen by more frequent personal intercourse. There is another point which recommends your societies to the engineers of the whole universe, namely, the pub. licity which they give to the various processes of production and manufacture, thus rendering a valuable service to art and science. What they do for the benefit of their own country is eagerly taken up by other nations.

What the Exhibition reveals is an immense progress in mechanical art; a progress which proclaims itself by an infinite variety of instruments and tools adapted to every individual strength for isolated labour as well as for the workshop. Owing to the large probable extension of manufactures, political economy had foreseen, in this agglomeration of human exertion, a cause of great anxiety concerning the moral influence which these powerful combinations might exercise upon society and amongst the working classes. It did not seem that this should be the fundamental law of industrial By this praiseworthy method England has labour, as it might lead to lamentable conse- proved that the advantage in commercial inter. quences, such as the separation of all the mem- course does not fall to the lot of the nation that bers of a family. Now it cannot be denied that keeps secret the processes of its labours, but to the the Exhibition proves a greater tendency towards nation that makes them known. We can apprebringing back labour to the homestead and ciate, better than any, the value of that lesson. workshop, rather than diverting it in the direc- Here, great and learned administrations, such as tion of large manufactories. the manufacture of arms, the construction of Mechanical science is subdivided into infini-ships-what we might style the state establish. tesimal sections suited to every fraction of ments-are isolated, and keep secret all progress the strength of man so that the minutest labours which might be of inestimable value to the world may now be wrought by machinery where at large. In your country and elsewhere, those children were formerly employed, in delicate branches of art incessantly in demand, from their and tedious manipulations. These remarks, Mr. very publicity acquire and spread the healthy President, must apply in a particular manner influence of the progress they have achieved. The to the objects which characterise your society, English Exhibition has the remarkable feature, as well as to many of its members. Amongst most fruitful in its results, that it teaches more the various societies of engineers which have by the agents of production then by the produce been established in England, those which take itself; and your scientific publications form the mechanical art as a basis in a manufacturing reflection of that teaching. point of view are those which retain the greatest vitality. I see two causes for this. The first is, that they are called for by ever increasing wants and demands; secondly, because their members are incessantly recruited by men who have been brought up in the workshop. These men necessarily gifted with instruction, without, which they would not enjoy either the confidence of their clients or that of their masters and fellowworkmen, are the most valuable assistants to the engineer, on account of their habits of labour as well as their skill, which is founded on long and actual experience. The engineer calls them to his side because they can understand him best. They are his natural successors. A society of engineers that would exclude them would not long survivel; whilst that society which admits them enlarges its sphere of inluence and of action as much by what it gives as by what it receives.

The many societies of engineers formed in England have set this example. They have thereby, recalled to mind their origin. Telford and G. Stephenson were the noble types of men whose own genius led them to appreciate that instruction of which they themselves stood in so In our last number we gave the address of the much need at the commencement of their President of the Society of Engineers to the career, much more than the intellectual power President of the Society of Civil Engineers of which they felt conscious they possessed. Their France. We now append M. Flachat's reply, whole life was one long study, accompanied by delivered at a séance on the 14th inst. M. the most wonderful practical achievements. Eugene Flachat spoke as follows:-Mr. Presi-Your engineers continue to follow in that great dent, in the name of the society over which I path. They are chiefly their own instructors; have the honour to preside, I thank you for the happy idea you have so ably expressed of establishing communications between the engineers of France and of England, with a view to their becoming more frequent and more intimate. The Universal Exhibition afforded an excellent opportunity for realising such an idea, and we express our thanks to you for having conceived it. We are, as you have expressed it, all en. gaged in a similar task. The identity of our labours and the objects we have in view alone establish a bond between us. One of the results of our Exhibition will be to strengthen that bond of union, as it proves, in a remarkable degree, that technical progress takes the lead in every. thing connected with industry, as well as in all works of public utility. There cannot, indeed, be any hope of the development of labour except through the advancement of the arts of manufacture; and our profession being called upon to promote this by all its activity and intelligence, we take the greatest interest in that progress. The highest importance which can be accorded to the Exhibition is the development of labour in all its branches, by bringing the intelligence of

and those who rise above the common level and
achieve a certain public celebrity only do so
with the double guarantee of experience and of
instruction. In the present day, when the pro-
fession of the engineers has become so vast from
the extent of its applications, it has been neces.
sarily divided into distinct branches; and, al-
though this subdivision cannot be regarded as
absolute, it may be said, without fear of contra-
diction, that machinery holds the first place from
its importance and general utility. This is why
we behold in England societies of engineers
formed in every great centre of industry, and
assume a high importance.

Our society has followed your example. It is
true, that it derives its chief element from en.
gineers educated at our learned schools, but it
gives a hearty welcome to men of experience,
who have thrown open to themselves the gates of
the profession, and, like yourselves, it places it-
self in constant contact with the great centre of
manufacturing industry, and with the great es-
tablishments of public works, thus enlarging
within proper limits its connection with men
whose interest it is to know and understand each

I cannot conclude this reply to your friendly and courteous address without thanking you for the wish it expresses at the end. Peace is the greatest of all blessings; and the Government that gives it has a claim to our gratitude. Amongst civilised nations peace can only exist on three conditions-the honour of the country, its power, and the development of labour. Our Government has made this triple object its task; yours has taken the same line, and the consequence is an intimate alliance between the two uations. This alliance is an expanding circle which will admit other nations as soon as their industry attains a similar development for it is labour which creates imperishable warfare. It is the path pointed out by Providence; the Governments that know how to guide us, and maintain us in that path, will have founded a new era.

NEW ORGAN FOR PENZANCE.

HE new Public Hall at Penzance is to be TH furnished with a grand concert organ, which has been built by Messrs. Bryceson, Brothers, at their factory, Brook-street, Eustonroad. We recently inspected this organ, which is handsomely, but by no means gaudily, decorated, and is of fine tone and great power. The organ consists of three complete rows of keys, CC to A 58, and independent pedal organ, CCC to F 30 notes. The great organ and manual couplers are played by means of the pneumatic apparatus. The bellows supply three hydraulic engines. The case is 32ft. high, 20fc. pressures of wind, and will be worked by wide, 11ft. deep, and shows a frontage of 16ft. metal pipes and projecting trumpets, richly decorated in gold and colours. On the occasion of our visit, the power and tone of the instru ment were fully brought out by the Brothers Le Jeune, who, although only 11 and 13 years of age respectively, executed alternately some of the most difficult and brilliant pieces by Bach, Handel, Meyerbeer, and other composers.

The workmen employed at Mr. Hampton's marl pit, Hanley, recently came upon an enormous fossil calamite 7ft. in diameter and of at present unascertained height. The outer rind, of the thickness of about a quarter of an inch, has been completely carbonised, while the whole of the hollow portion of the reed is compactly filled with stone abounding with impressions of calamites, ferns, and other vegetable exuvim of the carboniferous period. The uncovered portion of the fossil is about 70ft. from the surface.

gother. Thus a

JUNE 21, 197

JUNE 21, 1867.

ON GROVE'S GAS BATTERY*.

BY M. J.-M. GAUGAIN.

THE MECHANICS' MAGAZINE

that of a Volta's couple,

Zn- Cu
Acidulated
water

387

Arry's gatselement, and with the theory set to work by joining them by a conductor who dried amount of the

amongst us. There is scarcely a great ca happy relationship for manufactory where the member d ciety are not welcomed and instru fellow workman; and it is this result wit me now to express in the name of all the who constitute our society, our grate tEnglish societies who give us so bear come whenever we visit their indu blishments. For many years that kind given to all who have sought it has e a feeling of mutual good-will, which the les Ition will tend to strengthen by more fu personal intercourse. There is an which recommends your societies t gineers of the whole universe, namely, a licity which they give to the vari of production and manufacture, thus rele valuable service to art and science. We do for the benefit of their own countrying taken up by other nations.

By this praiseworthy method Engl proved that the advantage in commerni u course does not fall to the lot of the mi keeps secret the processes of its labour nation that makes them known. Wenn ciate, better than any, the value of the le Here, great and learned administrations, an the manufacture of arms, the constru ships-what we might style the state was ments are isolated, and keep secret alm which might be of inestimable valetti at large. In your country and elsewin branches of art incessantly in demand, in very publicity acquire and spread de mu influence of the progress they have sche English Exhibition has the remarkable most fruitful in its results, that it tea by the agents of production then by t itself; and your scientific publications in I reflection of that teaching.

I cannot conclude this reply to y and courteous address without thanking the wish it expresses at the end. Pas greatest of all blessings; and the Gre that gives it has a claim to our pain Amongst civilised nations peace can m on three conditions-the honour of the cy its power, and the development of how

Government has made this triple obese

Į yours bas taken the same line, and deme
quence is an intimate alliance betwen b
inations. This alliance is an expanding
which will admit other nations as so
industry attains a similar development-kri
labour which creates imperishable vari
is the path pointed out by Providen
vernments that know how to guide a
maintain us in that path, will have found

era.

NEW ORGAN FOR PENZANI THE Dew Public Hall at Peace

THE new Public Hall and commer

which has been built by Mess Brothers, at their factory, Brook-stret, i I road. We recently inspected this org is handsomely, but by no mess decorated, and is of fine tone and gres The organ consists of three compese keys, CC to A 58, and independent ped The great p 'CCC to F 30 notes. manual couplers are played by ma pneumatic apparatus. The bellows sum pressures of wind, and will b

LL physicists are acquainted with Mr.
of it which he has given. This theory is now
generally admitted; and probably few persons
remember the objections which from time to
time have been urged against it, especially by M.
Schönbein. I have been led by other investi-
gations to return to the subject; and although
I was not acquainted beforehand with M. Schön-
bein's investigation I have arrived at almost the
same conclusions. I used a mode of investiga-
tion quite different from those hitherto employed.
I only worked with one element at a time; and
instead of measuring the intensity of the current,
I measured the electro motive force directly by
the method of opposition. I could thus numeri-
cally estimate the influence of the modifications
which I have successively introduced into the
arrangement of the couple.

Mr. Grove thinks it indispensable that each
of the platinum electrodes in his gas-couple
should be simultaneously in contact with one of
the gases and the liquid beneath, In order to
ascertain if this really is so, I made the following
determinations.
I first measured the electro
motive force of a couple in which each of the
platinums touched at the same time the liquid
and the gas, as prescribed by Mr. Grove. I
then lowered the platinum wires so as to immerse
them completely and to keep the liquid from
contact with the gas; and having again mea-
sured the electromotive force, I found that it
was exactly the same as before. It follows
from this observation that the action of the
platinum only extends to the dissolved gas, and
that the jars containing gas have no other pur-
pose than that of keeping the solutions they

cover in a state of saturation.

I imagine, moreover, that I can explain why
Mr. Grove has arrived at an entirely different
result. By my method of observation, the
couple I used is only at work for a fraction of a
second; in so short a time the gaseous solutions
surrounding the platinum wires cannot be ap-
preciably altered. This is no longer the case
when the current is allowed to circulate whole
days, as by Mr. Grove it was allowed to do; the
liquid layers which then surround the platinum
wires are continually robbed ofthe gas they con-
tain, and must take fresh quantities from the re-
servoirs above; the gases, which thus dissolve

solely on the upper surface of the liquid, must
reach the platinum wires more easily the nearer

The electromotive force of the gas-couple
varies singularly with the condition of the pla-
tinum wires used. According to an old obser-
vation of Matteucci, the action of platinum
wires is increased by heating them in a spirit-
lamp flame some moments before using them as
electrodes. Under the most favourable condi-
tions the electromotive force of a gas couple
made with unplatinised platinum wires scarcely
exceeds 155. I take as unit the electromotive
force of the couple-
-that is to say,
that of a bismuth and copper thermoelectric
couple, one of whose junctions is at zero and the
other at 100°. As I have some time ago re-
marked, the electromotive force of the couple
varies in different elements even using
pura metals; and therefore the numbers which
I shall cite are not comparable with those which
M. J. Regnauld obtained when using a different
thermo-electric element from mine. I have
found that the electromotive force of the gas
couple is not modified when the oxygen bell-jar
is replaced by one containing carbonic acid, or
even by a jar which only contains boiled water.
I have found that the couple formed by joining a
platinum wire plunged in a solution of oxygen, and
a platinum wire immersed in water deprived of
gas developes no current. M. Schönbein had
observed these latter facts in the year 1843, and
concluded therefrom that in Groves gas couple
the oxygen serves to depolarise the positive wire.
I entirely assent to this explanation, and think
that the function of oxygen in the gas battery is
that of sulphate of copper in Daniell's battery.

The electromotive force of Daniell's element.
Za-
-Ca
is represented by 193;
Acidulated-Sulphate
of copper

water

*Philosophical Magazine. Translated from the Comptes Rendus.

by 178
when the two couples are at rest; but if they are
offering very small resistance, it is found, after
a few minutes, that the electromotive force of
the Volta's couple falls below 70, while the
Daniell's retains almost all its original force.
The explanation of these facts, almost univer-
sally admitted, is, that the algebraic sum of the
electromotive forces is almost the same at start-
ing in each; but, under the influence of
the current, the polarisation of the copper deve-
lopes in Volta's couple a considerable negative.
force, which diminishes the algebraic sum of the
forces of the couple, while in Daniell's element
the sulphate of copper prevents the polarisation;
in the same way, in Grove's element oxygen
serves simply to depolarise the positive wire.

It must, however, be remarked that the action
of oxygen in the gas couple is far from being as
effective as that of sulphate of copper in Daniel's
element. When a Daniell's element is set to
work by joining its poles by a short and thick
copper wire, the electromotive force rapidly di-
minishes, even when the couple is arranged as
Mr. Grove prescribes. I found in one experiment
that this force fell in a few minutes from 152 to
30. To establish this fact, it is necessary to
measure the electromotive force of the couple
which has been at work the moment contact is
broken; a few minutes' rest restores all its
energy. I have tried to find in what proportion
each electrode contributed to the enfeeblement
which the couple undergoes under the conditions
mentioned. I found that the electromotive force
put in play by the wire immersed in hydrogen-
was lowered simply by 26, and that the antagon
istic force developed by the wire plunged in oxy
gen was 96. In fine, it appears to me established
that the electromotive force put in play in Grove's
element is due exclusively, or almost so, to the
affinity exerted between the oxygen of the water
and the hydrogen condensed by the electrode of
platinum.

CHEMICAL COMPOSITION OF THE MUD
FROM THE STREETS OF THE CITY OF
LONDON.*

By DR. LETHEBY.
URING the last twelve months many analy
Do
ses have been made in my laboratory of
the mud from the City thoroughfares, with the
view of ascertaining the relative proportions of
horsedung to the matter from the abraded
stones and iron of wheels and horseshoes; and
the results show that the former material
averages about 57 per cent. of the dried mud.
It was first ascertained that the amount of
moisture in the street mud varies to a consider-
able extent, according to the state of the wea
ther, but it is rarely less than 353 per cent. of
the weight of the mud in the driest weather,
the average of ordinary weather being 48'5 per
cent., and in wet weather it ranges from 70 to
90 per cent. After all moisture has been driven
off from the mud by exposing it for many hours
to a temperature of from 266 deg. to 300 deg. of
Fah., the relative proportions of organic and
mineral matters were as follows; and for com-
parison the composition of well-dried fresh
been determined :-
horsedung and common farmyard dung has also

Composition of mud from the stone-paved streets
of the City, compared with fresh horsedung
and farmyard dung dried at 300 deg. Fah.:-

47.2 52-8 1000 1000 1000 1000 1000 The largest amount of mineral matter is always found in the mud in wet weather, when the abrasion of the stone and iron is greatest. At that time it may amount to 79 per cent. of the weight of the dry mud, whereas in dry weather it does not exceed 42 per cent. Taking the average of all weathers, the amount of horse dung to abraded matters is about 57 per cent. The exact proportions of stony and ferruginous matters in the mineral constituents of the mud have not been determined, but from the deep red colour of the ash obtained by incinerating the mud there can be no doubt that the propor

* Communicated by the author to the Chemical News.

STEAM FIRE ENGINES IN THE MIDLAND COUNTIES. Tadopted in our Midland towns is that THE first steam fire engine that has been recently supplied by Messrs. Merryweather and Sons, of London, to the Corporation of Nottingham. The engine is one of the makers' long stroke double-cylinder pattern, and discharges 500 gallons of water per minute to the height of 180ft., and is similar to the engine supplied by the firm to Liverpool. The trials which have just taken place with this engine at Nottingham have proved most successful, and at the grand trial there were present the Mayor (Alderman Thackeray), Alderman Heymann, the Chairman of the Watch Committee, the Town Surveyor, Town Clerk, and most of the members of the Town Council, as well as some four or five thou sand people. This trial came off in the marke place, one of the largest and finest in England. In eight minutes exactly from the time of lighting the fire, cold water being used in the boiler, 100lbs. of steam was raised, when the engine was at once set in action. Á 14in. jet was first thrown to twice the height of the figure of Justice on the Town Hall, or ranging between 170ft. to 180ft. in height. Two lin. jets were next projected simultaneously, and lastly, four in. jets all of which went far above the figure mentioned, The steam pressure stood at about 125lb., and the water pressure 1101b. and 13016. according to the jets thrown. Altogether the trials were regarded as most satisfactory, lasting in all about an hour and a-half.

ROYAL POLYTECHNIC INSTITUTION.. ROFESSOR PEPPER has been to Paris, PEO and the result of his trip is a very enter taining illustrated lecture on the subject of "A Visit to the French Exposition." On Tuesday. evening, we had set forth for the first time at the Polytechnic Institution, a pleasant trip from Newhaven to Dieppe and thence on to Paris, no point of interest on the route being left unnoticed. The Professor gives his audience some valuable hints respecting life in Paris, and lays before them monster plans of Paris and the Exhibition Building to which he conducts them by various routes. When there he accompanies them through the grounds, and lays before them immense pictorial representations of every person and thing worth inspecting there. After thoroughly reproducing all the most noteworthy objects of interest in connection with the present great peace festival in Paris, the Professor winds up with some excellent reflections and good advice. No person unacquainted with Paris should think of going there without, if possible, first seeing the Exposition from a Polytechnic point of view, which will enable him to see it properly and economically, both as regards time and money.

A letter from Cairo says-" We learn that in the last days of April, M. Miani, the traveler, set out for his journey of discovery in equatorial Africa. This gentleman proposes to prove that Messrs. Sp.ke and Grant have advanced erroneous statements in the account of their explorations about the Lake Nyanza. In a letter written from Suez, M. Miani says that he is expected in those regions by natives who were in his service during his first expedition."

the tools of one thousand revolutions per a these tools penetrating into the metal divide and agitate it very violently, atte time sensibly warming it by the rapid which takes place between the pre molten metal and the ends of the to turn and are moved in all directions in the of the metal.

JUNE 21, 1867.

THE MECHANICS' MAGAZINE.

389

lump of silver of the necessary fineness, obtained
either from the Government mixes or by melting
down Mexican dollars, is placed in an iron ladle
and reduced to a molten state by means of a
charcoal fire and a pair of blacksmith's bellows.
It is then poured into a mould, from which it is
taken out in the shape of thin rectangular bod
which are immediately thrown into a tub of cold
water. On being taken out, a man seated on the
ground shears off with a pair of large fixed
scissors all jagged pieces adhering to the angles.
They are now handed to another man, who
weighs them one by one, and a piece is cut off, if
necessary, to reduce the bar to its proper weight.
The next process is that of dividing the bar by a
fixed pair of shears into eight equal portions of
the size of ichibus; this is done by a workman
cutting it as accurately as his practised eye will
enable him, and his work is tested by weighing,
light pieces being rejected, and the heavy ones
reduced to their proper weight by the scissors.
The pieces are now heated white hot in a char-
coal fire, plunged into water, boiled, and washed
in a kind of brine, from which they come out
with a moderately bright surface. They are
next very slightly milled on the two sides, and
more deeply on the edges, by means of a milled
hammer. They are now ready for stamping. A
man places one of the pieces on a stationary die,
and lays on the top the other die; a second man,
armed with a huge hammer, gives one blow on
the upper die, and the coin is struck. The blows
are dealt in rapid succession, and the whole scene
reminds one of a blacksmith's shop. Boys now
punch small stars on the edges by means of

MACHINERY FOR ROLLING METALS.

T
HE firm of Petin, Gaudet, and Company,
ironmasters of Rive de Gier, France, is a
guarantee for the practical character of the
apparatus we are about to describe, and which
has been invented by the two gentlemen whose
names we have mentioned. The invention relates
to a mode of rolling T, double T, or U shaped
metal bars, as well as bars of a flat or rectangular
section. It consists essentially in the employment
of a pair of lateral adjustable rolls running loose
on vertical axes in combination with a pair of rolls
in horizontal axes, whereby the top, bottom, and
side or sides of the bar may be rolled simulta-
neously. The upper roll may be raised or
lowered by screw spindles or otherwise, to give
any desired thickness of metal to the rolled bar
and the two lateral rolls, which revolve loosely
on their axes, and which rotate by their contact
with the metal passing between. The horizontal
rolls may also be adjusted nearer to or farther
from the ends of the horizontal rolls by screw
spindles worked in concert or separately. These
several rolls are, of course, shaped in accordance
with the form of bar to be produced, and any
convenient arrangement may be employed for
giving motion to the main rolls, or, if desired,

chisels and hammers. The coins are weighed
one by one for the last time, and the light ones
rejected. The imperial stamp is added by means
of another stamped chisel and mallet, and the
PREPARING INDIA-RUBBER.
coins are complete. They are rolled up in paper
packets of 100; each packet is weighed, and
NDIA.RUBBER in one form or other is very
marked with a seal, which serves as a guarantee
largely used in many departments of art and
of its contents, and gives it currency as 100
manufacture, and its use is on the increase as
ichibus. While every operation is performed in
invention the better adapts it for its various ap-
this primitive manner, perfect order prevails in
plications. The most recent patent bearing on
the establishment; every man goes through his
the subject is that of Mr. E. L. Simpson, of
portion of the work in silence and with the
Bridgeport, Connecticut, U. S. His object is to
regularity of clockwork, and many evince consi-
produce a vulcanised india-rubber or gutta.
derable skill. There are about 300 hands
percha compound free from the odour or effects
employed in the building. When the men enter
of free sulphur common in vulcanised goods..
in the morning they are made to divest them
His invention consists in the combination of liu
selves of their own clothes, and put on others
seed or other vegetable oil, sulphur, and benzoin
belonging to the Mint. At the end of the day's
gum. He first boils the oil to the consistency
work a gong sounds, when the somewhat curious
of honey, to facilitate the preparation, and pul
spectacle is presented of 300 men springing from
verises the sulphur to a powder, thoroughly
the ground on which they had been seated,
of two ounces of the gum to one pound of the
mixing therewith the benzoin gum, in proportion
throwing off their clothes, and rushing, a naked
throng, to one end of a yard. Here they pass
sulphur. To each quart of the boiled oil he then
through the following ordeal in order to prove
of the sulphur causes the compound to act quicker,
adds one pound of the prepared sulphur-more
that they have no silver on them :-Their back
and less causes the compound to act more slowly.
hair is pulled down and examined, they wash
their hands and hold them up to view, they
This mixture is subjected to a moderate heat,
drink water, and then holloa, and, lastly, they
sufficient only to cause the substances to re-act
run to the other end of the yard clearing two or elevation of the improved arrangement of rolls, fluid to a semi-solid state, having a honeycomb
In our engraving, fig. 1 represents a sectional upon one another until they pass from a semi-
three hurdles on their way; after which per-
formance they are allowed to put on their own and fig. 2 is a corresponding horizontal half or spongy appearance; this forms the vulcanising
clothes and depart. Mr. Sidney Locock, Her section of the same along the line 1 2 in fig. 1. compound. Benzoin gum by its vapourising
Majesty's secretary of legation, from whose In the ordinary frame Care mounted the two qualities perfectly expels the fumes of the sul-
report of this year these statements are taken by rolls A and A', which roll the metal horizontally. phur as well as the odour from the oil, and ren-
the Times, believes that the Mint has been only The upper roll A is capable of vertical adjust-ders the compound nearly if not perfectly odour.
twice entered by foreigners, and states that the ment by means of the screws B and B. The
apparent absence of all restrictions with regard lateral rolls G and G' revolve loosely on their axes
to touching and handling the coins points to the g and g', which are mounted vertically in jaws
probability that it is not often open to the public; capable of being adjusted towards, or from, the
but he remarks that even if it were, the manners ends of the rolls A and A' by turning the screws
and customs of the country are not such as would D and D'; these screws may be worked simulta-
preclude a mixed assemblage of visitors from neously, if the rolls G and G are required to
going over it and remaining to the end. The be moved equally on either side, or they may be
quantity of silver being coined daily at the operated singly. Behind the two pairs of rolls
beginning of this year was 50,000 momme, which there is fitted a guard plate E, which keeps the

As soon as the metal hardens and ap the tool is changed; one of the works tool like that shown in fig. 8, for lifting which has become deposited on the ed furnace, while another workman cathe in all directions. When the metal is out and refined the cutting tool is wi and the puddler makes balls in t way, and takes them out of the farmace The kind of tools which are used to metal are worked with pulleys of h meter, and are heavier than the first of the metal becoming harder, and Force being therefore required to wat Che same reason the speed is consider gradually diminished according as the Comes more difficult to work, from abo revolutions per minute being sai Furnaces may be made with two or m Facilitate the work on account of the metal which can be worked at once. It will be well to have two corde each drum, the one serving for the s and first work, and the other which ha Conger serving for the large tools he metal is cut, and which carry greater diameter. By this means the Or lengthening of the bands or cord Cools are changed will be avoided The drums on which the cords or hould be long enough for the cards sufficient length to move over whe he movements or directions given by When there is not sufficient space r ong enough, cheeks or dises should be ach end of the drum of sufficient be ent the cords coming off. It is safe the straps to make the tools tur Fight or left. The point or end of the very heavy, should worke tadherenced

to the lateral rolls.

less, and when combined with india-rubber and subjected to a regulated heat will cause the same to undergo the change known as vulcanising. By this process of preparation and combination all the fumes of the sulphur as well as the effects of the sulphur upon other articles than the rubber and kindred gums vulcanised in the usual manner, are entirely destroyed.

In the preparation of india-rubber or other allied gums preparatory to being subjected to the

requisite beat, Mr. Simpson finds by experiment the following to be the proper proportions:-If

turns:

In 1840 the production was 20,963 tons, worth £ 9,339

In 1845
In 1850
In 1865

28,354 44,723 211,016

11,474 18,746

138,724

These figures are very instructive. The year 1864 produced 181,883 tons, which was only 2,913 tons less than in 1865; yet this difference for one year was greater than the entire production for 1845, and it may be mentioned that the one-fifth part of the whole population owes its existence and prosperity to The new mining laws have given, the mines. by the enlarging of the concessions, an extraordinary impetus to the great facilities for production. Regarded from a geognostic point of view, the Siegen mountains belong to the The ironstone seams Coblence-slate formation.

MANUFACTURE OF SPIEGELEISEN. 70 per cent. of iron, so that the production, even. for dry heat, one pound of india-rubber or gutta-RE EFERENCE has recently been incidentally with the high price which must be paid cannot made to the increased application of fully meet the demand, and there are many mines percha, two ounces of the vulcanising compound spiegeleisen; and, it is now proposed to give which formerly appeared to be unprofitable that above described, and eight ounces of litharge and some further details of that material which is would now give most satisfactory returns; the proper colouring material. To increase the produced from the steel-ironstone, or spathose indeed, a profit of from 25 per cent. to 100 per quantity at the expense of the quality, whiting ironstone of Siegen, to which particular attention cent., according to the thickness of the seam, the may be added to the extent of about eight ounces; is due, as being the district which contains the nature of the ore, and the distance of the mine mix all together in the usual manner by grinding principal working mines from which the spie- from the railway station, may be expected. The between heated rolls. If not for dry heat, the geleisen is supplied; indeed, the Siegen mining extent to which the production has already litharge may be left out. When properly pre-district, with that which surrounds it, forms the increased will be readily seen from the following pared the preparation may be applied to fabrics first and richest in Germany. From very ancient figures, which are taken from the official rein the usual manner of applying similar com- times it has been celebrated, and has long stoodpounds. Or it may be used independent of in many respects-through the excellence of its fabrics and rolled into thin sheets, or fashioned products and careful manipulation in the manuin similar manner as common india rubber or facture, &c. at the summit of the German iron gutta-percha, and cured by subjecting to the and steel trade. requisite heat in the proportion which the quantity of vulcanising compound bears to the quantity of india-rubber to be vulcanised, in like man. ner as for the common sulphur vulcanisation. This invention is peculiarly adapted for dental purposes, as the rubber now used for such pur. poses has incorporated with it large proportions of free sulphur for the purpose of vulcanising the rubber after it is formed. The odour and taste occasioned by the presence of this sulphur is extremely obnoxious to many persons, and occasions the principal if not the only objection to the use of rubber for dental purposes. To produce this rubber for dental purposes, to one pound of india-rubber or gutta-percha add ten to fourteen ounces of the above compound. The greater the quantity of the compound the harder will be the rubber. After curing, thoroughly mix the compound and rubber by grinding between warm rolls. Add chrome red or lake pink in quantities to produce the requisite colour, and when thoroughly mixed the substance will be in a plastic state, and in this state rolled into thin sheets and ready for the The dentist forms the plate in the ordinary manner as for other rubber, and when so formed it should be subjected to a heat of 320 deg. Fab. for about four hours, proportionately less time as the degree of heat is greater; other wise treat as ordinary rubber. The plate thus prepared will be as tasteless and odourless as metal plate, and will not tarnish the fillings or other gold in the mouth of the wearer.

dentist's use.

For the formation of articles "hard" or non

elastic the preparation is the same as for dental purposes, and when moulded into the desired form and cured the articles may be polished or finished in the usual manner of finishing similar articles of hard rubber. The preparation of rubber or gutta-percha when applied to fabrics, may be "flocked" in the usual manner of flock ing similar coated fabrics. For mechanical purposes, as for belting, hose, &c., commonly called fabricated rubber, several thicknesses of fabric are laid one above the other, and interlaid with a thin coating of the rubber prepared as first de

scribed.

THE SPENCER RIFLE.

TESTIMONY continues to be borne to the efficiency of the Spencer repeating rifle in practical use, as will be seen by the subjoined letter. It is dated New York, March 30, 1867, and has been received by M. Romero, the Mexican Minister at Washington, it appears in the United States Army and Naval Journal. Dear Sir,-As I told you when in Washington, General Aureliano Rivera, had twenty-five men armed with Spencer's repeating carbine, mostly officers and picked men: he was attacked by the famous Colonel Dupin at the head of 500 picked French troops. The French as usual charged sword in hand, but were driven back three times; they at last retreated leaving seventy-five soldiers dead, and about fifteen wounded. Dupin reported he had met a force of 1,500 Liberals in such a strong position that he was forced to retire. Several other cases have occurred in which the use of Spencer's carbine has decided in a few minutes the result of the action. General Rivera's success is in great part due to the use of said repeating carbine. I am sorry to say at last accounts he was entirely out of ammunition. I am glad to be able to testify to the efficiency of that weapon, and only regret we have not more amongst our troops. The engagement referred to occurred in the vicinity of Rioverde.-Very respectfully, your obedient servant, Enrique A. Mexia.

But during the last tentyears, whilst in England, Scotland, Belgium, and France, the progress in the production and manufacture of iron, favoured by cheap means of railway transport, has been in gigantic propor. tions, the iron industry of Siegen, through want of fuel and cheap transport, has remained far behind other iron-producing districts. The mining-and only the surface portions of the richest deposits were wrought at all-was conducted upon a limited scale, by small guild-like cliques, whilst the smelting business was in the hands of hundreds of partners, and, as well as the refining process, carried on entirely with charcoal; therefore, operations were mostly form in many parts wide-spreading layere. In limited to day-levels above the neighbouring the neighbourhood of Siegen the steep slate valley; only in a few pits have they commenced mountains show in many points of their deep to drive deeper levels, and even in those they glens spathose ironstone throughout, of ample only attempted to keep the water by such power thickness and extent. The principal formation, as was procurable from manual labour, or from and probably the oldest of the Siegerland a small water-engine. More, however, was but mineral deposits, is the spathose ironstone, with which the other metalliferous ores are almost little needed: workings to the deep were unThe method of working necessary, since the ore standing above the always connected. water level was far greater than the require-hitherto pursued in the ironstone mines of Sieger. ments. Added to this, the more the price of land gives evidence of the most tenacions coniron in England, Belgium, &c., descended, the servatism on the part of the owners of the more disadvantageous was it to the Siegen pro- mines. Through the great inquiry which has duction, aud the smaller was the sale obtained; sprung up for the spiegeleisen, there has been and hence, for the most part, these great already established in the neighbourhood of the treasures remained unutilised. Cheap and better railway station a blast-furnace, of which only provision of fuel, and cheap transit cost for the a preliminary mention need be made. The soheavy products, were the means of utilising called "Charlottenhütte," near Siegen, which them, and of placing the iron industry of Siegen has been scarcely three years in operation, in its proper position. gave during the last two years' work 20 per cent. and 33 per cent. respectively in the shape of profits, notwithstanding provision being made for the creation of a reserve fund. From these statements it will readily be seen that the development of the spiegeleisen trade of Siegen is likely at no distant period to add materially to the industrial resources of Germany.-Mining

The construction, in 1840, of a high road to the Rhine and to the coal district had such a

Journal.

BELGIAN ACADEMY OF SCIENCES.

favourable effect that, up to 1850, the produc.
tion of the mines and ironworks fully doubled.
It was a small beginning, but yet an ample
argument as to what might be expected in the
future from the construction of a railway. The
railway was made, and in 1861 the line was
with Cologne upon the Rhine, with the coal
opened for traffic. Siegen is now connected
districts of the Ruhr, aud with the upper Rhine,
in the province of Nassau. This now satisfied
as well as with the rich hematite iron deposits
has issued the four following subjects for
necessity has laid open an extraordinary field prizes of the value of one hundred francs, to be
for enterprise in the ironstone mining and awarded in the year 1868-1. Examination and
smelting business of the Siegen district. The discussion of the methods in use to ascertain the
riches of the district in the ironstone, so far as declination, inclination, and magnetic intensity
quantity is concerned, is incalculable, whilst its of the earth, as well as the secular and diurnal

quality entitles it to a place amongst the richest
in the world. The ores occur in such varying
qualities, that not only can they be wrought with
most lucrative results, but they will admit of the
production of the kinds of iron of the highest
qualities, and suited to the requirements of the
different markets into which it may be sent, and
of all the various degrees of hardness. Besides,
as the spathose ironstone is predominant, there
is a matchless material for the manufacture of
cast, blister, and puddle steel. For wire and the
finer descriptions of iron manufactures the Siegen
product is the best material, and yet this
excellent iron and steel-iron can be supplied at
quite as low a price as is paid in other places for
the commonest qualities. With proper technical
and economical management and direction,
therefore, there need be nothing to fear from
competition.

How much the Siegen spiegeleisen is now
sought after, owing to the easier and cheaper
railway transit, may be judged of from the fact
that this description is not only sent to England,
but also in considerable quantities to other
foreign parts. The continued increase in the
pig-iron production in the Rhine province and
in Westphalia has given rise to an enormous
inquiry for those ironstones, and by preference,
for the good Siegen qualities of brown ironstone,
Spathose ironstone, and the iron glance, which
last is frequently found to contain as much as

THE Royal Academy of Sciences of Belgium,

variation Discussion and improvement with respect to any important point of the theory of the form of waves.-3. A complete study of a natural organic alkaloid, containing azote and oxygen, quinine in preference to any other; the object being to elucidate the constitution of this substance, and to determine the place which it should occupy in serial classification.-4. The anatomic composition of the egg in varions classes of the animal kingdom, its mode of formation, and the functions of the various parts of which it is composed. The papers to be written in Latin, French, or Femish, and sent in before the August 1, 1868, with name of author, in a sealed letter, to M. Quetelet, perpetual secretary of the Academy.

During the past year the total production of the various quicksilver mines of the world was about 85,534 flasks, of which the Old Almaden of Spain and the Idrian mines of Austria supplied 39 625, while the remainder came from Calfornia. With last year's production, the accumulated stock in all the different markets in the world is approximately 120,000 flasks. For many years, the Spanish mines controlled the whole market, but worked, especially the New Almaden, which surso energetically have the California deposits been passed its ancient namesake by nearly 3,000 flasks last year, that the market is much more independent than it used to be.