Public ledger. [volume] (Memphis, Tenn.) 1865-1893, 1868-10-21

and through the apparatus by which the
temperature is elevated to the necessary
high degree. The actual development OF
heat, on the supposed ten feet square OF
the surface of the sun, will therefore
equal the amount of heat generated by
the consumption Of 100000 pounds OF
coal per hour.
The mind cannot conceive the intensity
which must accompany such an inordi-
nate consumption in so small space.
Still less can we form an idea Of the ma
ture of the combustibles, of their sutii-
cheney, when such an intense heat Is
perpetually kept up on the entire surface
of the globe, the diameter of which is
more than hundred times greater than
thet of the earth. But it is not my inten-
iion on this occasion to lay before the
philosophical faculty my speculatlonss
regarding the properties of the wonderful
orb; have only designed to discuss
the question as to the sufficiency OF the
radiant heat notwithstanding the enor-
nous distance, and the use we can make
of it as a mechanical motor. The result
of my experiments, as already stated,
having established the fact that without
an inconvenient extension of the me-
chanism which have devised for con-
centrating radiant heat, sufficient power
can be obtained for practical purposes, 1t
will now be proper to point out what
amount of mechanical power may be
obtained by occupying Swedish square
mile with solar enginee.
Assume that one-hslf of the area is
set aside for necessary roads, houses,
etc., an available area would remain OF
l8, ,000x36, 900 equal 648, 100000 super
fetal feet on which radiant heat might
be concentrated. My several expert
ments having shown that the concentra-
ton of the solar heat on one hundred
square feet of surface is more than
sufficient TO develop horse power, it
follows that Ga, 900 engines, each of one
hundred horse power, may be kept in
motion by the radiant heat Of the sun
on Swedish square mile.
Archimedes enthusiastically exclaimed
that his favorite device, the lever, had
power enough to heave the earth out OF
its path. 1t may be more truly said that
the concentration Of the radiant heat OF
the sun furnishes sufficient force to stop
the earth in its course.
cannot omit adverting to the insig-
nifcance of the dynamic energy which
the entire exhaustion of our coal fields
would produce, compared with the meal
culable amount of force at our command,
if we avail ourselves of the concentrated
heat of the solar rays. Already English
men have estimated the near approach OF
the time when the supply of coal will
end, although their mines, so to speak,
have Just been opened. A couple OF
thousand years, drops in the ocean OF
time, will completely exhaust the
coal fields of Europe, unless, in
the meantime, the heat of the sun be en-
ployed. 1t is true that the solar heat is
often prevented from reaching the earth
On the other hand, the skillful engineer
knows many ways of laying up supply
when the sky is clear, and that great
store. house is open where the fuel may be
obtained free of cost and transportation.
At the same time, a great portion OF our
plane. enjoys perpetual sunshine. The
field, therefore, awaiting the application
Of the solar engine is almost beyond COM
putation, while the source of its power is
boundless.
Enough, / trust, has been said to enable
the philosophic faculty to judge OF the
Importance of the subject, but who can
not see what an influence an inexhaust'
ibIe motive power will exercise on civili--
cation and capability of the earth to
supply the wants of our race