The evening times., 1899-04-11
THE WIRELESS TELEGRAPH.
MarcOni's Invention Tested by Sig.
nal Corps Omcials.


Col. C. o. Squier and his assistant. Ser
geant Bath. OF the Signal Corps. con-
Quoted successful experiment in wireless
| telegraphy in this city yesterday. The
| regular induction coil Of the Marconi sys-
| TEN was discarded. and new one, the
Tesla coil, connected with a receptacle fill
ed with refined oil. was used.
The instrument for receiving the waves
was placed in the corridor of the depart
| ment building and the heavy iron door
closed. The electrodes were started and
and the coherers of the instruments in the
| hall showed conclusiyeIy the effect of the
waves started from the inside.
The receiving instruments were then
| moved from the War Department side to
the Navy Department side, a distance OF
several hundred feet. The waves were ac-
curately recorded. 1t was the intention
| Of Colonel Squier to send a message over
the system, but the dynamo broke down
day.
Colonel Squier said the experiments of
the last few days were more to ascertain
the laws governing the system than to
demonstrate its utility.
Within a few days a message will be
flashed through space from Fort Myer, Va.
to some high point in Washington-possi-
bly, to the top of the State, War and Navy
building.
A set of instruments for sending must
be set up at Fort Myer. The receiving set
must then be taken there and gradually
removed toward Washington. in order to
gauge the height to which the wave-receiy-
ing pole must be elevated. Each succeed
ing wave describes a greater arc. and con-
sequently must be received at a higher
point.
When Washington is reached, il may be
necessary to set the receiver up on the
Washington Monument. Even should the
top Of the State. War and Navy Building
be high enough, it is feared that the vast
amount of iron which enters into the con-
struction of that building may seriously
interfere with the working of the instru-
ments.
Tests on a small scale have been made
at Fort Myer. as well as in the laboratory
at the War Department, all Of them sue
cessful. The instruments are as simple as
those used in ordinary telegraphy. and diff
fer little.
Sounds are originated by an ordinary
Morse key, and the reading at the other
end is made from a receiver like those in
ordinary use. The sending instruments
consist first OF an induction coil. Colonel
Allen and Colonel Squier believe the Tesla
coil gives better results. 1t does not
change the principle.
Communicating with the coil are two
brass spheres three inches in diameter.
approaching within an inch of each other.
The sending key is so arranged that a de-
preston Of the lever causes spark to pass
between the two spheres. These sparks
produce the waves. which radiate in every
direction.
Passing on through space the waves
come in contact with a wire elevated by
means Of pole above the receiving set.
and the pulsations are communicated to q
sensitive cylinder filled with steel filings.
BY means. Of what is termed the coherer
the wave motion is communicated to the
receiver. when the reading is made as in
everyday telegraphy. The Morse alphabet
is used in the writing. so that the chief
difference between the wireless system and
that now in use is the absence Of wires 1t
is feared by experts that in the wireless
system, conditions must approach too close
ly to the ideal to assure successful work,
but time may remove all obstacles.