Omaha daily bee., 1899-04-14
THE FIELD OF ELECTRICITY
Public Interest in the Development Of
Wireless Telegraphy,
SYSTEM EXPLAINED BY THE INVENTOR
Interesting Details of the Experi-
mcnts-PhysicaI Dangers of N-Rays
schedule of Telephone Rates
In Foreign cities.

Recent experiments with the Marconi sys-
TEN OF wireless telegraphy have excited pro-
found interest throughout the world. The
fact that communication was established
and maintained between Boulogne. France,
and Folkstone, England, thirty-one miles,
with only water and air intervening, is con-
sidered a remarkable achievement and fore
shadows possibilities Of vast Importance.
Similar experiments are to be undertaken
in this country, the FIRST between Washing
ton City and Fort Myer, on Arlington
Heights.
The Marconi system, says the New York
Sun, Is based upon the utilization Of the
Hertzian magnetic waves, which travel
through the lumlniferous ether with the
velocity Of light, and, in fact, were declared
by their discoverer. Prof Hertz Of Carlsruhe.
to be identical with light, except that the
waves are OF greater length. Whenever an
electric spark is made to jump from one
electrode to another these waves are pro.
duced, and their rapidity may be varied by
variations in the spark producing apparatus.
so that instruments used for sending and
receiving signals through their medium can
DE attuned to one another and made invul-
nerable to the attacks OF other waves OF
dissimilar periods. Wherever these magnetic
waves reach they affect all magnetic ma
terial, and thus make 1t possible 10 use them
as a means of carrying messages.
frot. Hertz also discovered that the waves
winch bear his name, although radiated like
light, in all directions. IL set into motion
from a free source, can be reflected and di-
rected, just as light is, by means OF mirrors.
III, therefore, you imagine an electric circuit
in a house, with a key in it, just like an or
binary Morse telegraph circuit. you have
the basis of Mr.. Marconi's system. This cir
cult runs through a spark coil with an os-
cillator or interrupter, to produce c%ontinu-
Gus sparkling so long as the circuit Is kept
closed by the key. and from this the secon-
Diary or sparkling wire runs out Of doors and
to the pole from which the messages are TO
be sent. The two ends of the wire termi-
nate in small metal spheres, between which
the sparks pass.
Early Experiments.
When Mr.. Marconi began his experiments
this was the complete form Of his sending
apparatus and readable signals could only
be sent a few yards. In his present form
OF apparatus one Of these wires is extended
TO the earth and the other has an extension
carried vertically into the air, and the
length of this latter wire bears a direct
relationship TO the distance over which sig
nails can be sent.
E'H NAN'ANNhA Hiov LOuIh Nv u MS
receiving apparatus already invented for
him by Prof. Calzecchi Onesti Of Fermo and
improved and modified by others. This re-
ceiver is what is known as a coherer. The
idea upon which 1t Is made Is that IL YOU
take an electrically conducting material like
iron and break 1t up into small particles
like filings the intervals which separate
these particles would prevent the mass from
allowing any current from passing through.
Now, II you were to bring a magnet near
to the mass Of filings each particle would
become magnetic, draw itself close to it's
neighbors and the mass would become so
solidified as to establish through it an cleo
trical channel.
For his receiving instrument Marconi uses
just such an instrument. 1t consists OF a
small glass tube four centimetres long,
partly flied with filings of nickel and sill
yer. At either end of this tube and reach-
ing into the mass OF filings is a terminal
wire of an ordinary Morse relay magnet cir
cult. One wire runs to the ground and the
other connects with the magnet, the battery
and the ground. The armature Of the relay
magnet opens and closes a strong local cir
cult, which in turn operates a recording
instrumen and also a little hammer which
continually taps the coherer to shake the
filings apart when they are not being hell
~ N6tNN A-N - 49,
up on a pole side by side with the sparkling
spheres, with a similar vertical conductor.
The Hertzian waves have the quality of a
magnet in causing the filings in the tube
to adhere to one another and the manner
of the operation OF the system is simple.
The operator presses his key. just as in
ordinary telegraphing making his alphabet
In dots and dashes. AS the waves shoe.
out and with the velocity OF light reach
the receiving station miles away the filings
IN the coherer there draw together and 5
current passes through them which draws
up the armature OF the relay magnet. THU
closes the circuit of the recording instru'
ment. and although the Taper is set to worn
10 shake the filings apart, the magnetic
waves come TO IL with such ~rapidity, each
one re-establishing the Conference, that the
slower acting recording instrument is mol
disturbed, and it continues to record the
signal so long as the far away operator
keeps his finger on the key. The tuning Of
the cCherer to waves of different frequen'
cies Is done by attaching to each end OF i
a copper strip. and the length OF these
strips determines their susceptibility to diff
ferent wave tones, just as the length OF ar
organ pipe fixes its note. MI. Marconi saic
1t had been discovered that the distance
over which he could transmit messages de
pended on the height of the vertical wires