The San Francisco call., 1899-05-12
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WASHINGTON, May 11-General
Greely to-day made the first authori-
tative statement as to the progress
made in wireless telegraphy under the
auspices of the United States Signal
Corps. The important conclusion is
reached by General Greedy that the
wireless system is not likely to sup
plant the ordinary method of tele-
graphic communication. The results
SO far obtained have been uncertain.
General Greely's statement is as fol-
lows:
Since the announcement of the tests
in space telegraphy by SignOr MarcOni two
years ago. the subject has been under
consideration by the Signal Corps of the
army, and recently experiments have
been begun to thoroughly test the value
of this means of communication for mill
tary and other governmental purposes.
Special apparatus has been designed and
constructed for these tests, and they have
already shown sufficient promise TO war
rant further systematic trials.
In view of the great public interest and
in order to facilitate experiments by other
scientists in the United States. 1t IS
deemed proper to put forth this statement
of operations to the present time
Transmittcr-In the experiments thus
far several forms of transmitter for the
generation of HertZian waves have been
used and much promise has been realized
from the use or a large ALTERNATING cur
rent coil in oil as a generator, instead OF
the ordinary RuhmkOrn coil employed by
Marconi This coil is energized by
horsepower rotary transformer, 1ur-
nishing l25 volts alternating potential, and
this arrangement makes very powerful
and efficient source Of Hertzian rotation.
ReceiveT-The former receiver used mas
been substantially the Brankey Co
herer" discovered in 1891. and the signals
transmitted are recorded upon receiv-
ing tape.
the west elevation of the State, War and
Navy buildings utilizing the present
wooden hagpOle as the vertical wire lor
the transmitter. The receiver was first
grounds, about three-quarters Of mile
distant. and later moved to the Signal
Corps station at Fort Meyer, Va.
During the experiments constant com
munication by heiograph and flag be-
tween the transmitting and receiving sta
tions has been kept up by the trained
men of the regular Signal Corps, and this
has greatly facilitated the Work or eX-
perimentinig Signals, letters and words
have been transmitted and received be
tween those stations, but the great dell
cacy and constant adjustment required
in the present receiver have made the
transmission Of regular messages as yet
unreliable and uncertain. Ine presence
Of large buildings and large masses OF
iron and metal necessarily present IN
cities make such places undesirable Tor
carrying on experiments OF TINS charac-
ter The distance over which signals may
be transmitted by given apparatus is
a function of the height of the vertical
wire used in either end, and this has
naturally suggested the use Of small gas
balloons such as have already been used
for signal and other purposes by the Sig
nal Corps. A supply of these balloons
has already been ordered and Will be
used for this purpose in the near future.
That there is a field of usefulness for
space telegraphy is undoubted, but that
II VIII supplant to a material extent the
use of wire for ordinary commercial
telegraphy is not believed. It's value for
connection between lighthouses and light
ships at sea and to replace ordinary flag
methods in use between naval vessels,
should prove invaluable, since darkness
or storm have no effect upon its use.
The use of metal reflectOrs to augment
and direct the radiation to particular
Doints has already met with partial sue
cess and should be thoroughly inVesti-
gated At present the radiation proceeds
from the transmtter in all directions and
the same message can be received at any
point within the proper radius at WHICH
a receiver is placed. satisfactory d.
recting reflector and a receiver of the
proper electrical capacity, or, in other
words, tuned TO the vibrations OF the par
ticular transmitter, would make a great
advance in space telegruphy and do much
toward the extension of its field of prac-
tical usefulness.
While secrecy of transmission is among
the probabilities, the present stage OF eX-
pertinent does not Justify It's positive pre-