The San Francisco call. [volume] (San Francisco [Calif.]) 1895-1913, 1898-10-31
SEA TELEGRAPH
REVOLUT|ONzED
Rapid Transmission Of
Information.
GENERAL GREELY'S REPORT
VALUE OF THE sINE-WAvE
SYSTEM.
Experiments Prove the Superiority of
Alternating Currents Over
the Methods low
In Use.
Special Dispatch to The Call.

WASHINGTON, Oct. 90.-One point
in the annual report of General Greedy
has escaped public attention owing to
it's disassociation with the late war. 1t
relates to the discoveries of two young
physicists, Professor A. c. Crehore and
Lieutenant Colonel George O. Squier,
volunteer signal officer, who have lately
pursued, under the direction of the
chief signal officer of the army certain
scientific Investigations that promise
to work a revolution in methods of
ocean telegraphy. General Greedy ex-
presses his belief that these discoveries
and inventions have assumed such
form and phase as to be of the greatest
value to the commercial world. The
discoveries outline the true scientific
methods Of telegraph known as the
sine-Wave system.
The first experiments were made at
the Artillery School, Fort Monroe, Vir
ginia, and were discussed theoretically
in 1897 under the title of the ''synchrono-
graph" a new method of rapidly trans
hitting information by the alternating
currents. The next step was the test
ing of this system on a long telegraph
line, and for this purpose Professor
Crehore and Colonel Squier visited
England, where they were afforded
every facility for experimental work
over the Government telegraph lines
through the courtesy of the Postmaster
General and the distinguished electri
clan, Chief Engineer Preece.
The experiments, the report sets
forth proved conclusively the superior
ity of a modern alternating current
"a m which
is a simple sine wave as compared with
the system now exclusively used
throughout the world in code teleg
raphy. Under the sine wave system
words were sent and received over
line 100 miles long at rate of over
5000 words per minute. Under this new
system the speed of the Wheatstone
commercial receiver was increased as
much as threefOId when operated under
identically the system of, the old code
of telegraphy. The superiority of the
sine wave having been decided by eX-
perimental apparatus, the next step is
to construct transmitters for actual
commercial conditions. Two special ap-
paratuses were devised, one for operat-
ing land lines and the other for the
transmission of messages over long
cables. The cable transmttter was COM
pleted and land instruments advanced
when the late war interrupted prog
ress, which has only lately been re-
newed by direction of General Greedy.
The first practical tests of the cable
transmitter have just been made
through the courtesy of George Clap
perton and other officials of the Com
merciaI Cable Company of New York.
The experiments were made over the
cable between New York City and
Canso, which had length of 827 knots,
and electrical resistance of 1900 Ohms,
and an electric distributing capacity of
231 nicrofards. These tests were made
between September % and October 16,
1896
The change from existing Geographic
methods consists in the substitution for
the present appliance of a transmitter
sending smooth waves such as are OBJ
tanned in alternating currents working,
without makir- any other changes
whatever in the elements of the present
system. The conditions in the trans
are distinctly and widely different from
those on aerial lines The necessity of
increased speed over ocean cables, the
report continues, while not generally
is strikingly obvious when
examined from q commercial stand
point. Since every cable spanning the
Atlantic costs several million dollars
the value of any discovery that will in
crease the working power Of these ca
bles is al. once apparent.
General Greedy says he has no ,hes1ta-
ton in expressing the opinion that the
sine wave system, which also admits
of easy duplexing, will, within year
or two. increase very materially the
working capacity of every cable to
which it is applied.