Evening star. [volume] (Washington, D.C.) 1854-1972, 1908-04-05

THE end OF the WOllQ coal supply II olly
i a few generations away. That means the
passing of our chief power generator Another
source of energy must be found, and speedily.
The waterfalls are by no means adequate tor
the purpose, nor are the hckle winds Inc
enormous force wasted in ocean tides still
presents problem that battles those seeking
to make it mans servant.
There remains for hope the m1ghtIest
reservoir of power, the sun. Compared win
it, all other springs of energy become lnslg.
niicant Professor Langley said that, II all
of Pennsylvania coal deposits were burned
in a single second, the resultant heat would
not be a thousandth part of the amount hber-
ated in the same time by the surface OF the SUM-
The matchless dynamo of the heavens waits
ready to our need. We have but to COntr1ve
a means to store and to direct its pOtence.
To that end men of science have been labor
ing for years. The earlier results were meager.
but more recently such a measure OF success
has been achieved that may dare believe
in ultimate triumph
Early Solar Engines
As early as 1871. Muchos gave to the Pans
n Academy of Sciences an account of a solar
engine which he had constructed. This con-
sisted of the surface of a straight truncated
cone, of which the generatrix was inclined
forty-fve degrees to the axis With this
was small cylindrical boiler, lying concentric
with the axis of the cone. The mouth of the
cone was turned to the sun, IN such manner
that Its prolonged axis WOulu SlIlke us lllluule
point the result was that the suns rays fell
in the funnel and were reflected by its polished
surface perpendicularly against the boiler,
Steam was thus generated; but the apparatus,
while demonstrating the principle OF the solar
motor, was of no practical value.
John Ericsson. the great inventor and me-
chanic was more successful. Writing in 1876
If his achievements, he gave much space to Il
description of his solar engine. In construc-
ton it was very simple: merely conlcal mir
Tor or reflector which received the heat OF the
sun on as large an as was desired and was
practicable. and directed it to focus. At the
focusing point was either a steam boiler or an
air cylinder, of which the contents became
heated to high temperature and were thus
made available for IN a steam or air engine.
Ericsson estimated the energy of his engine
as being one horsepower tor each one hundred
square feet of receiving area A condition IN
this calculation was that the day should be
clear and bright.
Nearly two score years ago, Carl Guntner
showed a solar engine of his own invention at
the Vienna Exhibition. Since that time he
has given much attention to the problems
advance This had a reflector made up of
plane mirrors, which, he thought, would
not prove too expensive either in the making
or in maintenance. The great number of
mirrors were long and narrow. Each revolved
about horizontal axis, and by means of a
simple parallelogram motion was made to fol-
low the sun in such manner that all the
suns rays that fell on the plane mirrors
were reflected to the surface of tube or boiler
having its long axis in the plane of the mirror
axis
The devices thus far described had little