The Prince George's enquirer and southern Maryland advertiser. (Upper Marlborough, Md.) 1882-1925, 1915-11-26
FIGHT ON SUBMARINES
pETECTOR SYSTEMS CONSID.
Erred BY THE SCIENTISTS.
Thought to Be Most Effective Method
of Combating This Most Deadly of
All Modern Naval Weapons
OF Warfare.

The prime advantage of the subma-
rine-its ability to escape detection
through sight-has been overcome by
the invention for use by the entente
allies of means of detecting it's pres
ence through hearing. The exact ma
ture of some of the most essential fea-
lures of this invention has, Of course.
been kept secret, but general de-
scription of it's manner of working is
given in the Scientific American. One
of those who contributed to the de-
velopment Of this detector system is
William Dubilier, an American elec-
trical engineer with numerous wire
less telephone and wireless telegraph
inventions to his credit. He had gone
to France on the mission of installing
wireless telegraph apparatus on air
craft, when he was called upon to aid
in solving the submarine detector
problem. Dubilier went to Cherbourg,
an important French port on the Eng
lish channel, where he found Profes-
sor Tissot of the French Academy of
Science, hard at work on the detector
system.
For some time before this, devices
had been contrived by which it was
possible to detect the sound waves
made by submarines, but these de-
vices also conveyed the noises made
by the propellers of all kinds of craft,
and they were of little value, because
fn dio-
tinguish the sounds made by sub
marine from those coming from other
vessels. Fortunately for the inven-
tors, however, it was discovered, in
the course of the tests, that the I'M
derwater craft were the sources Of
sound waves of exceedingly high ire
quency, quite distinct from any other
subaqueous sounds. While the cause
of the high-pitched sound is known to
the inventors, it cannot be divulged
since it would, then, be possible for
submarine constructors to eliminate
1t still remained to the inventors to
eliminate all other sound waves from
affecting the detector and also to de-
wise means by which the distance of
the submarine and the direction Of it's
travel could be determined. 1t re-
quired several months of careful ex-
perimenting to develop suitable res
onance tubes for filtering out unde-
sirable sounds. At first the device
finally developed, worked at a distance
of few miles and then its range was
increased to SO miles, by use of the
Audion amplifier, an American inven-
ton. This system is used all along
the coasts of the British isles and
France. 1t is not available for use on
vessels because of it's extreme sensi-
tivity An illustration shows the form
of the device as it lies in the water
a cable reaching out from shore and
ending in the sea in eight branches,
each with a rounded object at the end,
somewhat resembling a telephone re-
ceiver-a microphone. Each micro
phone is placed in such manner as
to receive sound waves best in one
direction. Accordingly, by listening
to the sounds received by the different
microphones, and slowly moving a
switch over the several contacts, the
operator can determine in what direc-
ton the submarine is moving. How
the distance of the submarine is de-
tected is kept more strictly secret.
Means of communication are main
tanned between these detectors on
shore and numerous vessels which are
sent out to attack the submarines.
Since the appearance of the Scien-
tific American article, the New York
Times relates that DR.. Lee de Forest
of New York, inventor of the Audion
amplifier, has received hurry-up call
from the British government and has
sailed for London. The use Of his,
amplifier in the submarine detectfon
device attracted the attention of the
British to him, and his services are
desired for cOntrivance of system by
which the approach of Zeppelins can
he detected at great distance. The
Times says that the form of Audion
used by the British in detecting sub
marines is not so highly developed as
the most recent of the De Forest in
ventions Doctor de Forest proposes
to work out a system similar to that
used for detecting submarines by
which not only their sounds will be re-
corded, but their distance and the d.
rection in which they are travelling
will be known.