The Liverpool Standard and General Commercial Advertiser.
Liverpool, Merseyside, England, 1842-01-18 00:00:00

LIVERPOOL POLYTECHNIC SOCIETY

The above Society held its Annual Meeting on Friday
evening last, at the Royal Institution, when after the dispatch
of other private business, the following gentlemen were
elected officers, and council, for the present year.
President.—John Grantham, Esq., C.E.
Vice-Presidents.—John Cunningham, Esq., F.G.S., Henry

Dawson, 'Esq.
Treasurer.—Benjamin Platt, Esq
Secretary.—C. F. Salt, Esq.
Council.

Dr. Reynolds, I Rev. T. Dwyer, A.M.
Mr. H. Booth, I Mr. R. H. Chilton,
Mr. A. King I Mr. J. Wlnnes,
Mr. Robert Mather I Mr. T. Clarke,
Mr. Robert Crosbie, Mr. E. Woods.

NEW PROCESS OF MANUFACTURING BRICKS, TILES.
ARCHITECTURAL MOULDINGS, &C.
The members afterwards adjourned to the large lecture
room, when the SECRETARY read a communication from
1?. Prosser, Esq., C. E., Birmingham, on his patent process
of mant!facturing bricks, tiles, architectural mouldings, kc.
The invention is applicable to the manufacture of any articles
that can be produced under a press. In the ordinary mode
of making bricks, the clay is prepared by suitable machinery,
and mixed with water to temper it. and reduce it to a plastic
state, fit for brick-making. All these laborious processes
used to be performed by the hand, in the open air; but lat-
terly much manual labour has been superseded by" horse and
steam power, in the operations of grinding the wet clay be-
tween rollers, and tempering it in a machine called a pug-mill,
which is an iron cylinder set upright, in the axis of which an
upright shaft revolves. Several knives are attached to this
shaft in a spiral manner. As the upright shaft revolves, the
clay thrown in at the top is wet, and kneaded, and forced
through an aperture in the bottom of the pug-mill, and by
this process it becomes tempered, ready for the moulder.
Large quantities of water are used in the tempering process,
in order to make the clay soft enough to be forced into the
moulds ; and this water must be got rid of, by a slow drying
process, before the bricks can be burned. Each thousand of
bricks, when ready for the kiln, weigh about half a ton less
than when they are first moulded. This half ton of water has
to be evaporated before the bricks can be burned. The no-
velty of Mr. Prosser's process consists in the clay being
dried, ground to powder, and submitted to pressure. in me-
tallic moulds, until the particles cohere together. As there
is no water in combination with the clay, no drying process
is necessary ; consequently the articles made by this method
are ready to be fired or burned as soon as they leave the ma-
' chine. Owing to the great pressure required to cause the
particles of clay to cohere together, the articles made by this
process have greater density than those made in the ordinary
way ; they are also less porous, and not subject to decay by
wet or frost. In addition to these advantages, any architec-
tural device may be impressed upon the clay, which, when
burned, will retain all the sharpness of the original, however
elaborately finished.
By this process bricks can be made in all weathers, and
with greater economy than by any other plan known at pre-
sent. The brick-press is worked by hydraulic pumps, giving
about 300 tons pressure, thus producing the adhesion of
cohesion. The machine delivers the brick (four at a time in
the present machine) ready at that instant for the kiln, re-
quiring no exposure to the atmosphere to dry. The whose
operation, from the time of putting the powdered clay into
the machine to the delivery of the brick, occupies about half
a minute. Machinery might readily be constructed to pro-
duce fifty bricks in a minute. This invention is likely to
work a revolution in the style of buildings in this country :
the most elaborate Gothic may be produced at no very great
cost. An outlay of £2,000 or £3,000 in machinery will
produce to an intelligent licencee many thousands a year.
The SECRETARY exhibited a brick made by this process.
It attracted much attention.
The SECRETARY also exhibited some specimens of buttons.
They were truly elegant, and were very much admired. At
the present time, about 5,000 gross of buttons are made
weekly, at Messrs. Minton and Boyle's, at Stoke-upon-Trent.
The demand for them is greater than can be supplied by the
present number of presses.
" IMPONDERABLES."
Mr. ADIE read an interesting paper on the subject of " im-
ponderables." The object he had in view was, he said, to
show the value of the law of the diffusion of fluids to assist
us in forming ideas of matter which cannot be weighed by
mechanical means. There might exist in nature fluids having
a sensible ponderability, whose exact weight could easily be
assigned, it experiments or observations in any collateral
branch of science could be produced to show the velocity
with which the matter in question would, under a known
pressure, flow into a vacuum. The general law for the dif-
fusion of fluids was that they flowed, under like circum-
stances, into a vacuum with a velocity inversely as the square
roots of their densities, or specific gravities. The hypothesis
of Dr. Dalton, that particles of one gas act as a vacuum to
those of another, had been confirmed by the experiments of
Dr. Graham and others, and the fact that they flowed into a
vacuum with the velocity stated, was established by experi-
ment. The extension of this law, (the concession of which
was required to his argument) was, that in addition to its
governing all known fluids, it also extended to those of whose
existence at present we have only strong suspicions—namely,
the imponderables, heat, electricity, magnetism, the retherof
astronomers, &c. The imponderables, if material at all,
must be aerial fluid, and subject to the laws of fluid, unless
they can be shown to be an exception to that as yet known
universal law.
After noticing the difficulty that presses against the belief
in the immateriality of heat (yet unresolved), the lecturer
reverted to the old corpuscular theory, which, sustained by
the highest authority, still claimed attention ; and on this
theory the law for the diffusion of fluids was a valuable
servant

" To show the weight (he continued) of practically speak-
ing imponderable bodies, let me suppose we have a room
which we can fill with atmospheres of different fluids at
pleasure, all of them under a uniform standard barometric
pressure of 30 inches. In addition to this we must have a
close vessel communicating with the room by an orifice that
can be quickly opened. If, then, the air be exhausted from
this vessel, and the orifice opened, it will be found that the
atmosphere air in the room will flow into it with a velocity of
from 1300 to 1400 feet per second. If the room be filled suc-
cessively with gases of various known densities, the velocity
with which they flow into the room can be easily predicated
from the known rate and density of air. For example—
Vapour of camphor would f10w.... 570 feet per second.
Carbonic acid gas..
Atmospheric air, taken at a quer-1 1320 „ Pt
ter of a mile per second
Vapour of water
Hydrogen gas 5OOO „
What, then, would be the velocity into the close vessel of a
supposed fluid, with a ponderability so small as to require
the most skilful analysis to detect its weight. A gas weigh-
ing a quarter of a grain for 500 cubic inches may be taken as
the type of such a body. It would be 620 times lighter than
our atmospheric air, and would consequently flow into a
vacuum with a velocity of nearly 61 miles per second. Any
aerial fluid lighter than this must remain imponderable by
direct experiment in our laboratories, though in large masses
its weight may be very considerable. Suppose the room
filled with heat or light still under the same barometric pres-
sure, if we could measure the velocity with which they pass
through the orifice, their specific gravity might be calculated.
Their velocity is so prodigious, that we possess no means of
measuring their velocity under 30 inches pressure, but astro-
nomers supply evidence on this head. The velocity of light
has been found to be 195,000 miles per second. The amount
of retardation, when it passes through an atmosphere of 30
inches' pressure, is also shewn by experiments on refraction,
from which the rate at which light or heat would flow into
the close vessel might be assumed to be ascertained. On
the corpuscular theory, then, of heat, it diffuses itself into a
vacuum with a velocity of 195,000 miles per second. Atmo-
spheric air under similar circumstances flows with a velocity
of a quarter of a mile per second. These velocities are in-
versely as the square roots of their densities : hence the spe-
cific gravity of heat, on this view, is the 608-billionth part of
air, and the weight of a cubic mile of such an aerial fluid is
nearly 1500 grains—a weight so far beyond the limits of
ponderability with reference to our senses, that it must be
augmented 100 million times before it could be practically
weighed."
The lecturer then carried his calculations according to this
law, to reckon the specific gravity of an infinitely more atte-
nuated fluid—the tether in which the undulations of light
have the vast velocity mentioned. Sound vibrated in air
with a velocity of 1130 feet per second, and such air had a
diffusive force of 1320 feet per second. Here sound suffered
a retardation of 190 feet per second, and light vibrated
900,000 times more rapidly than sound. Making a calcula-
tion, therefore, on the principle before stated, the diffusive
velocity of tether, according to the Dynamic law, was
136,000,000,000 of miles per second. He had reck-
oned the weight of a sphere of tether the size of our earth,
and, supposing it to be weighed under like circumstances to
air of standard pressure, the weight would be very nearly 70
grains. If the diffusive velocity thus given be borne out,
the whole woight of the tether in the vast sphere of solar space
assigned by Herschell to be 100,000 times the mean diameter
of the earth's orbit—the aggregate of the 70 grain spheres
necessary to fill with tether this great sphere, may be judged
of, when it is considered that their total weight would be
equal to our solid globe taken 71- times. The lecturer then
proceeded to deduce an hypothesis that this medium (tether),
though yet unsettled, was the basis of all atoms of matter,
and that these, less or more compressed, formed oxygen,
hydrogen, mercury, and so on, or other primitive bodies.
" This view of the subject," he said, " would leave us less
perplexed as to the source of iron and nickel found in the
composition of meteoric bodies which sometimes reach this
earth—nay further, even as to the comets themselves."
" I do not know," he continued, " if these considerations
will be objected to on the ground that they extend too far for
mortal ken. Certainly, in the present state of our knowledge
they are not ripe• for decision, but it must be remembered
they all appertain to inquiries into the laws of matter, where
it has been permitted for the faculties of man to receive from
nature the development of so many of her perfect laws.
Should a grand extension of those laws ever take place in our
day, I do not think there would ever be any ground to fear
evil, from a momentary feeling of exultation or pride for• the
step attained ; because it would be sure to be quickly sub-
dued by a contrary feeling of reverence and awe for the great
Author of all, of whose works we had only succeeded to un-
derstand the first link."
In further treating of the ascertained velocity of light, he
showed how, by simple steps, astromoners rose to some of
the beautiful conclusions they attained. He explained the
trigonometrical mode adopted by them to measure the sun,
moon, and other objects not approachable. An accurate base
line on this earth (its diameter) was the fundamental ground-
work from which we deduced all the sizes and distances of
the planetary bodies. The distances of the sun and planets
being ascertained by systems of triangles, the law of gt avita-
tion enabled a skilful analyst, from a few observations of po-
sition, to predicate the path of the body. The path and dis-
tance of the planet Jupiter had by such means been long
known. The times of revolution of his satellites, and, con-
sequently, the periods of their occultation behind his disk
were equally well ascertained. The observed occultation was
behind the calculated one, by precisely the time required for
the velocity of light at the rate of 195,000 miles per second.
Herschel had truly said, that to form any conception of this
vast velocity we must compare it with objects we know, and
lie institutes a comparison between it and a cannon ball, also
the flight of a bird, He (the lecturer) might be allowed to
add a comparison with a locomotive 'engine. In the time
that the five feet wheel of such an enginetravellingat the rate
of 40 miles per hour, makes a single revolution, light will
pass through a space equal to 50,000 miles, or nearly twice
the circuit round our globe.
He concluded by saying—" The physical astronomer,
whose enquiries are conducted independently of all external
objects, can do little without observations of positions of the
heavenly bodies, furnished him by the practical observer;
while the united labours of these two classes would always be
expressed in terms involving at least an unknown quantity
the size or weight of our earth, until they associated them-
selves with a third class, who are devoted to experimental
science ; for their task of weighing and measuring the earth
is a question of a purely practical nature ; so that even here
we may read the lesson we are all taught should govern us in
private life,—l mean our• dependence on one another."
A GENTLEMAN put some questions to the lecturer on the
mode of measuring the distances and dimensions of heavenly
bodies by means of an imaginary base line—the diameter of
the earth. These elicited some satisfactory explanations.
JOHN RossoN Esq., alluded in eloquent terms to the
progress and beaefits of the society. With reference to the
specimen of bricks produced, he considered it incumbent on
on
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climate. He proposed a vote of thanks to the council of this
society, for their exertions and ability in promoting its inte-
rests. He noticed, in conclusion, the advantages that had
arisen in France from similar societies;---stating that the fine
docks of Hamburg were designed and built by members of
the Polytechnic school. He anticipated the happiest results
from the progress of the society to the town at large.
The motion was unanimously carried, as were votes of
thanks to the lecturer, to Mr. Prossor, to Mr. Rosson, and
other friends, and to the proprietors of the STANDARD, for
the facilities afforded them in reporting their meetings. These
were for the most part feelingly acknowledged, and the
members adjourned to the committee-room, where, before
separating, they partook of tea and coffee.