The Grangeville globe. [volume] (Grangeville, Idaho) 1907-1922, 1915-10-21
Submarines Betrayed by Sound Waves

| The submarine has long depended for
It's defensive powers on the fact that,
travelling below the surface OF the wa
ter IL was invisible to the crews OF
surface ships Thus 1t can approach
it's target without attracting attention
| TO itself and, at the opportune moment,
after raising the peniscope a trifle
above the water to secure 3ts bearings
and maDeuver into the most favorable
position for attacking the enemy. fire
a torpedo at fairly close range.
But while the submarine may be In
visible when so desired, 1t rs not noise
less, and therein lies its weak point
which has now been made use OF In a
system for betmying the presence OF
underwater craft Not only is 1t possi-
BILE at the present time to detect SUBJ
marines at a considerable distance
away, but the same apparatus employ
ed for that purpose can Also be used
10 determine in what direction the
craft may be travelling as well as it's
probable speed Thus -1e great ad-
vantage of this type Of fighting vessel
1.-The very one that is it's raison detre
has at last been nullhied by causing
the ear to detect what the eye cannot.
their unprecedented campaign against
the English and French shipping, ex-
perts i'm the latter country have been
at work In experimenting with devices
Cor detecting the presence of submarines.
But they encountered only slight sue
cess. Microphones of various patterns
placed in the water caused the detec-
ton OF revolving submarine propellers
several miles dlstant-but SO with the
steamer propellers and those OF battle
ships. cruisers. destroyers, motor boats
and other craft, not to mention the
washing of the water against the near
by shore and thousands of ohter unde-
sirable sounds. In the babel of sound
the original objective was completely
lost track of, hence the aforesaid slight
success,
At this stage of the experimenting
william Dubiier an American electric
al engineer with numerous wireless tel
ephone and wireless telegraph inven-
tions to his credit, at that time in
France on the mission of installing
wireless apparatus ON aircraft, was
called upon to aid in the solving of
the submarine detector problem. Du-
bilier went to Cherbourg, an important
French port ON the English channel,
where he found PROT Tissot of the
French Academy of Science hard at work
on the detector system
1t is obvious to anyon familiar with
electricity and sound waves that the
problem OF evolving a successful micro
phone system for detecting the pres
ence of submarines by noises peculiar
to these craft was most difficult one.
Yet, unless uhe obstacles are actually
met with, vt Is impossible to form an
accurate conception of the great amount
OF thought and ingenuity that had to
be enlisted In evolving a satisfactory
| apparatus.
In the earlier experiments the French
simply placed waterproof microphones
below the surface of the water for the
purpose of gathering the sound waves
and listening to them by means of
telephone receivers. At first the sound
waves emitted by the propellers of sub
marines were those sought but these
were found to resemble so closely those
OF other craft that they could not be
relied upon. Fortunately for the expert
mentors, 1t was discovered In the
course of the tests that the underwater
craft were sources of sound waves of
exceedingly high frequency. quite dis
tinctive from any other sub-aqueous
sounds. While the cause of the high
pitched sound is known to the invent
ors, 1t cannot be divulged since it
would then be possible for German sub
marine constructors TO eliminate the
source Of the tell-taie sound waves and
thus render void the purpose of the
detector installations.