formulae and results of analysis in the two sub
jects. Maxwell said light was an electromagnetic
action. The undulatory theory of light, already
established, said light was a transmission of energy
through an elastic medium by a vibrating action.
Maxwell said this undulatory action is electro
magnetic : the two have the same properties and
. characteristics, deduced analytically from the for
mulae based on experiments in the two subjects.
In 1884, I designed a scries of experiments for
producing a magnetic field or an electric current
directly from the solar radiation, which would be
a direct proof of Maxwell’s analytically predic
tion. No XIX of Faraday’s Researches showed
that a magnetic field rotates the plane of polarizn
tion of a beam of light. Would rotating the plane
of polarization of a beam of light passing through
the other or material substances set up a magnetic
field? [A brief description of apparatus and experi
ments read from Electrical Engineer, March,
1889.] The imperfect apparatus and bad condi
tions fordoing such work in the old college build,
ing prevented the obtaining of a positive answer
from this series of experiments.
In September, 1889, Dr. Sheldon published, in
the A met lean Journal of Science, some experiments
of his, identical in principle on the same subject,
claiming a positive result in the affirmative. This
was questioned by Dr. Brackett; and there were
some articles in the Phil. Mag. by English physic
ists on their experiments in this line.
Turning from these attempts, whether more or
less successful, at direct experimental proof, we
have an unquestionable experimental proof in the
work of Dr. Herlz, though not quite so direct.
He showed that electric discharges, which are
oscillatory, set up undulations in the surrounding
ether having the properties knowu to be possess
ed by the undulations constituting light, and mov
ing with the known velocity of light.
It is no longer necessary to seek to verify by
direct experimental proof the electromagnetic
nature of light. What is called light, and is known
to be identical in nature with both shorter and
THE FREE LANCE.
longer radiations than effect the eye, is electro
magnetic. The solar radiation, the energy com
ing to us from the sun, is in the form or state pro
ducible by various apparatus and known to us as
electromagnetic.
The world, at one time using only muscular
energy to do its work, and not having capacity to
use other ; then rising in capacity and using some
natural forces, as wind and water; later using, for
some three hundred years, steam power; has now
sufficient capacity to use, and its needs are call
ing for, a less costly, more efficient, and in many
respects very different source of power. Half a
million, or more of men are doomed to the coal
mines, and to pay a human life for every 100,000
tons of coal. And then the energy of but one
fifth, or less, of this can be utilized through ther
mic engines; moreover, the very apparatus pre
cluding its application to uses which the age de
mands ; for, among other things, greater speed on
the earth must be had, and the air must become
a highway of travel. The million, or two or
three millions of laborers, directly and indirectly
engaged in coal work must be freed for better
work; and energy must be available so abundant
ly and cheaply, 111 a form to be used so efficiently,
by apparatus of such adaptability, that the whole
army of labor needs to be engaged in the strife for
material existence but a few hours daily.
Determinations of the “solar constant,” the
energy per square minute per second received
from the sun, show that on a surface about nine
feet square, perpendicular to the solar rays, one
horse power is received. This, however, is really
the energy measured after it is transformed into
heat. Unless the transforming substance has an
efficiency equal to unity, the actual downpour of
energy is greater than the accepted “solar con
stant.” But, at the least, here is an outpouring
on the world of an inconceivable, inexhaustible
supply of energy. And this energy is in the very
form or condition that the world in this age
wants. Moreover we have machinery for utiliz
ing this form of energy with an efficiency, under