Steam as a. moving power. 183

‘coals; Now 12 cubic feet multiplied into 1694 cubic feet or volumes gives
20,328 cubic feet of steam, which amount represents the precise quantity
of water which would occupy its place when such steam is reduced to the
temperature of 40° F., antl which we will suppose would rise 35 feet high
w-liic-h we areaware exceeds notonly the average, but the maximum bar-
onretrical column. It therefore only remains ton1u'tiply the aforesaid 20,-
328 cubic feet into 62% pounds, and that product by the assumed altitude
the water is raised in a vacuum, viz., 35 feet when we shall have the mad-
imum effect nature is capable of accomplishing, viz., 1,270,500 lbs. of wa-
ter raised 35 feet high, or, 44,467,500 lbs. one foot high, with one bushel of
the best Newcastle coal.

Havingshown the maximum effect that can be accomplished by the ap-
plication of the atmospheric steam, generated by a given quantity of fuel,
my next object will be to demonstrate that high pressure steam, when ap-
plied expansively, cannot produce so great an effect as atmospheric steam,
thereby, meaning to_ infer that no high pressure engine can perform the
same amountof duty as a condensing engine, both consuming equal quan-
tities of fuel. This is’ my _delibera,te opinion, founded on theoretical and
practical experience, and which coincides with the opinion ofalmcst every
practical engineer whom I have consulted on this important subject. But
what says the authority before refered to ?—for in this as Well as in the
former question, just discussed, my arguments shall be drawn from the es-
tablished laws of nature. .

1st. That the sum ofsensible. and latent heat in steam is a constant quan-
tity, viz,, about 1l72° F. , A , _

2ndly. That all matter, (steam, of course, inc1uded,) whether 5olid..li-

.quid, or gaseous, from, the most dense and refractory tovthe least ponderal

_ble, evolves caloric on compression, or increase of specific gravity, and ab-
sorbs culoric on dilatation, or when its specific gravity is diminished.
Brdly. To convert equal quantities of water of any assignable tempera-
ture, and under like pressure into steam of given temperature and elastici-
ty, requires equal weights of fuel tobc expended; but, although equal
weights of water must absorb equahincrements of caloric whm atmos-
pheric steam is generated, it does’ not follow that all the caloric absorbed in
high pressure steam is exclusively supplied by the fuel expended. The
law maintained is simply this, that the “same causes produce the same ef-
fects. .
4th1y. That steam of two, three, or more. atmospheres elasticity, is not
composed of two three, or the like number of volumes of water contained
in an equal volume of atmospheric steam, when generated under the sauna
barotnetrical .pressu re, but contains, proportionably less water as the pres-
sure under which the steam is generated increases. ' , 0
In proof of the foregoing theorems, Ibeg to adduce the following'ex-
perirnents and observations: , ~ ‘ .
lst. If steam be blown through. and condensed in a given weight of wa-
ter of._any’prev_iously determined temperature, until the said water arrives
at, say, 212° F.,.the quantity or. xveight of water added by such condensa-
tion"= will be preciselytlre_satne, whether the steam employed he of atmos-
pheric, double, treble, or more elaslicity,therehy‘establishing the extraordi-
naryfact, that all sensible. caloric, exoeed»ing 212° F., positively goes for
noth.ing,vit havingbecome latent bye dilatation. In this experiment, it is
necessary to observepthat the .steam~cond.ensed haslost no caloric by radia-
pon till aftersuch steam was.convertedjntovapor, and the effect sought had
i3¢gq'_a;1;’,..p1;Vodr:tce‘d,,,‘,» How, then r a s_avin.g, of fuel can arise by-the use of high.
pressure steam. wo"rk-ledexpansiveliy isto»-me auevident paradox, unless by

some power utterly beyond -my comprehension; the sensible caloric can