The Sun.
London, England, 1865-12-25 00:00:00

Manchester Literary and Philosophical

Society

At the last meeting of this society, Mr. R. Smith,
Ph. D.R.F.S., the president, took the chair.

THE QUESTION OF THE SUPPLY OF FUEL.
Mr. J. BOTTOJILEY said that a recent paper on
the employment of the internal heat of the earth led
him to consider what might be the condition of the
atmosphere when coal, lignite, anthracite, and all
other forms of vegetable fuel should be so exhausted
that the human race would be compelled to resort to
this source of heat. The numbers obtained led him

to the conclusion., that the exhaustion of the coal-

fields implied more than the depriving of the human
race of a ready source of warmth, viz., the alteration
of the atmosphere to an extent that would ultimately
prove fatal. As the latter assumption seemed to him
repugnant to reason, he would infer that long before
the exhaustion of the coalfields, the carbonic acid in

the atmosphere beyond limits of safety to life, would
have been decomposed by vegetation ; moreover,
as plants decomposed water, there would always be
some combusitible compound of carbon and hydro-
gen ; in other words, there will and must be abun-

dance of fuel in the world in all ages, if not of so
dense a kind as anthracite and coal, yet of some na-

ture intermediate between these fuels and vegetable

tissue, the origin of all varieties. The effect of

vegetation in maintaining the purity of the atmos-

phere has long been known. The assumption that
this agency is sufficient to furnish an abundant and

perpetual supply of fuel to mankind involves no new
principle, but it tends to establish a new inference
upon principles already acknowledged. Liebig
states, in his " Chemistry in its Application to Ag-
riculture and Physiology," (3d edition), that the
quantity of carbon existing in the atmosphere
amounts to more than the weight of all the plants
and of all the strata of mineral and brown coal
existing on the earth. This would seem to favour
the notion that the mineral and brown coal avail-

able for combustion would not affect the atmos-

phere to any serious extent if consumed. He has
assumed more carbonic gas to exist in the atmos-

phere than many authorities would allow. Moreover,
since the book was written enormous deposits of fuel
have been discovered. In another passage Baron
Liebig seems to favour an opposite view, but he
states, "in former ages, therefore, the atmosphere
must have contained less hydrogen, but a much
larger proportion of carbonic acid, than it does at
the present time, a circumstance which accounts for

the richness and luxuriance of the earlier vegeta-
tion." Dumas and Boussingault say, in their book
on the chemical and physiological balance of organic

nature, "If we suppose, then, that the whole of the
carbon was diffused through the atmosphere in the

shape of carbonic acid prior to the creation of orga-

nised beings we shall see that the atmosphere, in-
stead of containing less than I,oooth part of its

bulk of carbonic acid as at present, must have con-

tained a quantity which it is not easy to estimate,
but which was perhaps in the proportion of 3,4, 5,
6, and even 8 per cent." Mr. Hull, in his " Coal-
fields of Great Britain," taking 4,000 feet as the
depth capable of being worked, estimates the supply
from the English and Welsh coalfields at 60,000,000
ton for 100 years. In the same book it is stated
that American coalfields are 72 times greater than
the English and Welsh. In the reports furnished
to the Admiralty some years back by Dr. L. Playf air
and Sir H. De La Beebe, there is given a table
showing the average composition of Welsh, New-
castle, Lancashire, Scotch, and Derbyshire coal.
The mean of these numbers is as follows :—Carbon,
8040; oxygen, 7.16 ; hydrogen, 5-11. Subtracting
from the amount of hyrogen the quantity corres-
ponding to 7.16 of oxygen, there remain as combus-
tible material in one of coal—carbon, 0.8040 ; hy-
drogen, 0.0421. For combustion it requires 2.428
parts of oxygen, and produces 2.9480 parts of car-
bonic acid. Sir J. Herschel, in his Meteorology,'
takes as the approximate weight of the atmosphere
11 by lOilb. If we take as the amount of oxygen
in the atmosphere 23.04 per cent. by weight, and as
the amount of carbonic acid .05 per cent. by weight, I
the following numbers are obtained (assuming 1 by
1011 b. as the unit of measurement) :—Weight of
atmosphere, 110.000; oxygen contained, 25.344;
carbonic acid contained 55 ; weight of coal, 98.112;
oxygen required for combustion, 243.59 ; carbonic
acid from combustion of coal, 289.23 ; total-carbonic
acid, 344.23; ratio of oxygen to carbonic acid at pre-
sent, 460.8 to 1; ratio after combustion of assumed
quantity of fuel, 729 to 1. The last ratio can of
course only be regarded as an approximation, but
when we take into account all the available fuel in
the world—wood, peat, lignite, coal, anthracite,
also the quantity of carbonic acid evolved from vol-
canic districts—and remembering the opinion of a
member of this society, that we know little about
the difficulties likely to be encountered in mining
operations at a depth of 4,000 feet—there seems
little reason to doubt that the ration of the oxygen
to carbonic acid would be reduced considerably
below the number above stated, and that the
quantity of carbonic acid in the atmosphere would
reach a point much beyond that at which it becomes
deleterious to human life. It seems then more
reasonable to take the alternative and maintain that
the carbonic acid will be de-oxidised, and that
there will always be an abundance of fuel.
THE ORIGIN OF SOME MECHANICAL INVENTIONS.
A paper was read entitled " Notes on the Origin
of several Inventions, and their subsequent appli-
cation to different purposes." Part 11. By Mr. J.
C. Dyer.—The following are the principal portions :
—The Employment of Steel for Transferring En-
gravings : At the beginning of this century, upon
the death of Washington, medals to commemorate

that event being called for, Mr. Jacob Perkins
(then a silversmith at Newbury Port, near Boston),
undertook to supply them, and, as they were re-
quired in large numbers speedily, he devised a sum-
mary process of transferring the engraved design,
from prepared steel or stamps, by which he obtained
several from one original die, and thus a vast num-
ber of medals were rapidly produced. Shortly
after Mr. Perkins-applied the same principle of
transferring engravings for bank notes, on which
very elaborate designs were printed to prevent or
render their being forged very difficult by the hand
of the engraver. To effect this he produced cast
steel plates, and decarbonated their surface to the
depth of about 1-16th of an inch, which were thus
converted into very soft and pnreiron ; the letters
and designs for the notes being then engraved upon
them they were case-hardened and tempered for
use, but in lieu of printing from these plates they
were used as dies for making others to print with.
His next process was to prepare a cast steel cylin-
der, which in like manner was decarbonated at the
surface, and then under a strong traversing pressure
it was rolled over the letters and figures engraved
on the hardened plate, and these engravings were
taken up in relief on the surface of the soft cylinder.
This cylinder being then hardened, was used to
transfer, by means of the same traversing
pressure, the entire work upon its surface, to
any number of copper or soft plates for printing
with. The adoption of this plan by several banks,
for having very elaborate engravings on their notes,
turned the counterfeiters upon other banks whose
notes would be so much more readily forged, which
led to an extended demand by the other banks. In
the year 1809 Mr. Perkins communicated to me the
details of his process of transferring engravings,
with a view to having the invention patented in
England for our joint account. From the success
of his plan in America its adoption here was anti-
cipated, and still further development of it looked
for from the higher state of the graphic arts in
London. With this view I took out patents, and
minutely specified the method of carrying the in-
vention into effect. A very beautiful design was
then obtained from the classic pencil of the late Sir
R. Smirke, RA., which was engraved by Reiinback,
on prepared steel, for printing bank notes. But I
could not succeed at that time to induce the Bank
of England or any other bank to adopt the plan,
nor could the booksellers then be made to perceive
the importance of the transferring system for illus-
trating books, for which it has since been so exten-
sively used. The time had not arrived when public
attention could be drawn to the bank note forge-
ries as a national evil and the disgrace of hanging
men for a feat so readily performed as that of forg-
ing the one pound notes then in general circulation.