Custer weekly chronicle. [volume] (Custer City, S.D.) 1890-1931, 1909-03-20
HOW THE WIRELESS
TELEGRAPH WORKS
Scientific Explanation of Mar
coni's Great Discovery
Sounds Very Simple
Indeed.
BY Edaar Lucien Larkin.

Low Conservatory, Echo, Mt, Cal.
Drop stone into the surface of lake at
rest. Circular waves will expand In every
direction on the plane or fiat surface. If
similar disturbance could be made in air
the waves would traverse every direction
and the complete wave front at the limit
would be a sphere. Any light object on
the water or suspended in the air would
move slightly.
Suppose we fire a revolver in still air, q
disturbance would be set up and waves
started that would be translated into
sound by a distant tympanic membrane
in an ear. Firing rifles or revolvers so as
TO represent dots and dashes in the waves
thus established would not work. So they
fire the giant force electricity across a
narrow air gap between carbon points. The
electricity is stepped up to very high pres
sure-voltage in the carbons. Finally the
pent up force becomes so great that II
breaks the resistance OF the almost nom
conducting air and rushes across the other
carbon with immense speed.
This disruption of the air starts wave
as does a stone falling I'm water or the
discharge OF gun in air. But the out
burst OF electricity is many thousands OF
times more powerful than either. The
sharp sounds heard by those near wire
less telegraphic transmitter have nothing
TO do with the message. They are sounds
due to air waves. But wireless tele-
gram could be sent through space devoid
or air, for the waves are ELECTROMAGNETIC,
not aerial. They move in either, supposed
to iii all space and all matter. Many de-
vices have been made to secure sparks
through air-gaps. Condensers Of electric
ity have been employed at high pressure.
Dynamos giving rise to different wave
lengths are In daily use, also, at lower
pressures. Wave characteristics are modi-
fed In a number of ways, and also meth
ala ~fTtn
be set up whose lengths vary between on
men and as much as a thousand miles.
There is an incredible number of lengths
IN between these, so telegraphers will have
little trouble In selecting any length and
making sending and receiving instruments
IN tune as agreed upon. Suppose these
should be tuned to wave-length of 100
feet; then others with instruments attuned
TO 30 or ITO feet could not cut the others
message out of space and hear what was
being sent.
The electricity, from whatever source,
Is turned into and cut out of the sending
apparatus by an ordinary telegraphic key,
which makes and breaks the circuit
Suppose it Is desired to typewrite tele-
gram as received. Then the power is not
sent on the magnetic waves from the send
Ing station. This would require enormous
supplies of electricity. Waves are sent as
usual; these are received by delicate mech
anism wholly unable to print anything.
But sensitive apparatus receives the in
coming waves, turns on power from local
sources, and this actuates the printing de-
vices. The circumference OF the earth at
the equator is 24S9S miles In order to
telegraph around the world" il would be
necessary to send through not more than
half this distance from nation to nation.
And no doubt exists but that II will be ac-
complished Wireless telegraphy Is one Of
the most impressive conquests of nature
ever made by man.