The Ordway new era., 1914-05-15

enoulO cnOOe6 SOUND waves instead Oh
electrical waves for his controlling i'm
pulses. because sound will travel four
times as well and four times as far
through the water as It will through
the atmosphere.
Gardner showed that he could ar
range the sensitive receiver on his
submarine 30 that It would respond
either to one chosen note or to .
chord OF them, and unless all Of these
were sounded simultaneously the sub
marine would be Indifferent to the
tonA waves. OF course 1t was not long
before the military critics picked this
system to pieces. They declared that
these sounds could be detected by .
suitably arranged submarine signal
receiver. and they asked: What would
prevent an enemy from producing the
same tone or tones under water and
thus neutyalizing or completely upset
ting the sounds intended to operate
the little boat or . torpedo similarly
equipped!'
An ordinary man would perhaps
have been nonplussed by such stu.
alton. because to the average mind the
whole scheme depended upon the em-
ployment Of audible signals. for how
otherwise could the desired pitch be
chosen? You don't know John Gard
ner, 20 you can't realize what It means
when his lips set firmly and his square
chin takes ON an added touch Of
angularity. Just the same. picture to
yourself this outward show Of de-
A>~ nN~~ - 80
full man.
In all Of its essentials the Gardner
receiver II . mechanical substitute for
the human ear. It is far simpler than
the ear. because in that there IL re-
ceiving apparatus which boasts some.
thing like 5000 extremely minute
fbers constituting the terminals Of the
acoustic nerve. Each Of these nbers
IL responsive only to particular note
and 10 deaf to all others.
But the human ear has its limita-
tons There are sounds that 1t cannot
hear. sounds whose vibrations are eth
or too few or too many.
He set about making his receiver
still more sensitive SO that 1t would be
affected by inaudible sounds. This was
not 30 pushing a. It may appear at
first blush. He had only to ind some
sound producer which he could control
to q nicely and which then would be
capable Of creating vibrations higher
than those that would be detected by
the sharpest Of hur,an ears.
OF course he had to have for this
purpose a resonator that he could con-
troll perfectly, and once more electrici.
ty came to his aid. No. he did not
use q submarine bell or submarine
horn of . complicated nature. but In
stead he devised . way to turn q ship
iself into q source Of sound.
He has made It possible to cause the
hull or skin Of \ weasel to CULVER 10
that II will send these impulses speed.
ing through the water like rays radiat.
Ing from . source Of light He uses
an electromasnet which he places pre-
fersbly down below water and in the
very bow Of the craft. and the poles or
terminals Of the core Of sdis 0aSnek
are Close to but not in contact with the
inner surface of the ships steel skin.
An electro magnet Is active only
when current flows through the en-
veloping coil. and then streams OF mag.
netism dow out Of one end of the core
and circle around the coil and return
by the other end Of the core. The
speed with which the magnet Is ener.
gixed or de-energised will set up cor.
responding vibrations in the adjacent
plating. II these vibrations are not
too fast sound will be produced which