The mirror. (Stillwater, Minn.) 1894-1925, 1920-04-15
THE WIRELESS AGE
Some Day Our Light Heat and Power May be Taken Dret
From the Air.

Chautauqua Circle by Fl. p.
dred millions parts reaches the particular re-,
ceiver to be affected. When the key of the
transmitter is depressed, as much as fifty
horsepower must be projected into space in
order that an infnite-simal part of it may
be feebly detected as signal by an instru-
ment three thousand miles away.
Other wastes, too, must be reckoned
with by the designer of wireless telegraph
apparatus besides the waste in electric waves.
When a powerful spark is to be employed
for long distance signaling, there is leakage
of current which it is impossible to control.
Besides, every building, every obstacle on the
face of the earth absorb part of the energy
sent forth.
If you would understand, in general
way, the manner of realizing this amazing
possibility, you must understand the full
meaning of resonance. Begin with the
swinging pendulum of your clock. What
keeps it going? Nothing but little push
mechanically delivered at the right time.
Any freely swinging object can be kept in
motion, even though it weigh tons, if it is
given the slightest push by single finger,
but always at the right moment. Indeed,
the amount of swing can be increased enor-
mo,lsly by successive pushs correctly timed.
Everything in the world has natural period
of vibration. A hundred men can capsize'a
twenty thousand ton battleship by running
rhythmically from one side of the deck to
the other and carefully timing their move
ments to the frequency of rolling.
If the natural period of a hfty-story sky
scraper's vibration were known, boy with
tack hammer might shake down the entire
structure by persistent tapping at correct in
tervals. Such is the cumulative effect of
many little blows.
This principle of timing small impulses
so as to produce large effects is the principle
of resonance When you rule the rim of a
wine glass with your finger and make it ring
with clar musical note, you apply it in pro-
ducing sound waves. You can also apply it
in producing electrical waves, and that is
what Mr. Telsa has done. This great in
ventor has proven when conducting some ex-
periments in the high altitude of Colorado,
that te entire earth is electrically resonant
to certain vibrations.
Suppose it were possible to construct an
apparatus which would set up electrical
waves in the earth, with an apparatus which
would be the electrical equivalent OF the
bows tack hammer that could throw down
the monster sky scraper suppose that it were
possible to pile electric impulse on electric
impulse uneil the accumulation of them all
would represent millions of horse power in
electric oscillations; suppose that you have
way of turning tiny part of that unthink-
albe amount of power into motor to run
street car, light electric lamps, and perform
other useful work; suppose that you could
impress the faint modulations of your voice
upon the electrically vibrating globe, surely
that would be the millennium of electricity,
surely that would be the most stupendous
achievement in the ANIMALS of engineering.
Yet that dry, uncommunicative patent
granted to Telsa discloses means of setting
up the waves to which the earth is electrical
ly resonant.
But the designing of an apparatus for
emitting waves to which the earth is electri-
cally responsive is only part of the inven-
tors task. He must transmit his energy
without loss to the point where it is wanted,
which he claims is feasible. Strike tuning
fork, so that it vibrates and emits musical
note, bring that vibrating fork near a piano,
and you will find that of all the strings in
the piano just one will sing in sympathy.
1t will be marvelously different globe
from that which we know if Telsa's vision is
realized. As wine glass vbrates with
sound when its rim is rubbed, so the. earth
will vibrate electrically when it is subjected
to the action of millions of impulses correctly
timed. And those impulses will be impaired
by gigantic induction-coils Incorporated In
immense, towering steel cages, each not un-
like the steel skelton of huge Office building
in course of construction. In every large
city, you will see such a steel frame, project
ing far up into to the sky, overtopping houses