Massachusetts spy and Worcester advertiser. [volume] ([Worcester, Mass.]) 1823-1825, 1823-10-22

is heated to the high temperature of 400 de-,
grees, and that this produces the predictions
pressure of 500 pounds on the square inch.
When it is considered that MANY of the an.
gines now in use, are calculated for steam of
an elastick force hardly equal to hundredth
part of that employed by Mr.. Perkins. and
that none has before been constructed for a
greater pressure than IS pounds on the square
inch, the cause of the amazing difference be-
tween his and other engines must be at once
perceived. 1t will be recollected that in the
experiments of Mr.. Woolf, the highest TEMPER
allure to which he raised the steam was but
2o2 degrees, which produced pressure of 40
pounds on the square inch. 1t appears then.
II the accounts be correct, that by the addition
OF i50 degrees of heat, the power of thegsteam
is increased 400 pounds on the square inch;
but the increase ofpower is probably in sort
OF geometricai ratio with the additions of heat.
1t is also stated that the steam. after it has
driven the piston, and while ii is passing into
the condenser, acts with counterforce of 10
pounds to the square inch; and the useful
power oil the engine is set down at the differ
ence between that and 500 pounds, which is
40o pounds. But the conclusion is not strict
ly correct; because the resistance upon the
piston OF the forcing pump, while it is exerted
TO return the water or vapour into the genera
tor, ought also to be taken into the account
and this resistance, as it proceeds from water
or steam of as great elasticity as that which
acts upon the piston ofthe engine, will be pro-
portlonate to the area ofthe piston of the fore.
ing pump.
But some persons" it seems, are not vet
content with referring the vast power of the
new engine to any known and Ineligible prir-
ciples, so fond are they of whatever is mar
vellous or mysterious. Hence it is supposed
by these wonder struck philosophers, 6 that
the portion of water which escapes must nee
essarily carry off a quantity of heat from the
adjoining stratum (the temperature of which
may be thus reduced below the freezing
point, y or that, 6 in virtue of some new law
ofthe transmission ofheat, under the combined
conditions of elevated temperature and high
pressure, while the water, also, is forced to
remain IN contact with the red hot generator,
the whole water in the boiler may be laid I'M
der requisition to furnish the discharged fluid
with ITS necessary supply of calorick." In
other words, they suppose that the water,
which II expelled from the generator, carries
with it more than its proportion of heat, and
that Its expansive force is thereby greatly i'm
creased: but how this singular operation takes
place, is as inexplicable to them as Redheif-
er's perpetual motion has been to others.
Much is said, also, about the g red hot gen.
orator." and the tired hot fluid" fit be
true that the generator and its contents are
brought to a red heat, their temperature must
be much higher than has been supposed; for
the point at which body becomes luminous,
or at which Ignition commences, has been
fNr,n L
grees Farenheit.
Mocha NICK