Evening star., 1919-03-23

SS5a r III .f2sSa5
CAPT. r. H. LEIGH. U. 8. NJ, i,
In charge of anti-submarine war for
American forces i'm European waters.
opinion. The secret of detecting the
presence of an unseen vessel had been
solved!
The ships steamed back to Nahant.
A long-distance call was put in for
the Navy submarine base at New
London.
Rush three submarine chasers to
In due time they appeared. The
party started out again, were Joined
yard, and anchored off the Massachu-
setts coast line.
One submarine at a time submerged.
The subchasers equipped. with de-
tectors, followed her every movement,
charted her position, reported to each
when everything was in readiness
rushed to spot just over the sub.
Dummy depth bombs were dropped.
The submarine rose to the surface.
She had been within fey feet Of her
charted position.
And now the apparatus was about to
demonstrate its most valuable service.
A series of practical tests proved be-
yond the possibility of a doubt that
the detector could successfully diff
ferentiate between the sounds made
by surface craft and the sub. The
submarine noises were distinctly Pc
culiar to itself, and the instrument
translating this sound to the trained
ear brought home the message just
as you. when you pick up the long
distance telephone receiver, can
identify the voice at the other end Of
the wire.
The Victor Talking Machine Com
pany of Camden, N j., was now called
upon for its contribution to the in
vention. Phonograph records of the
various sounds heard by the observer
were made and catalogued, thus pre-
serving a complete record Of the ac-
complishment of the device. The rec
ords were used principally in training
students to identify the submarine
noises and detect the difference be-
TWEEN submarine and surface craft.
* X
Further tests were made. Shore lis
tening stations were set up. During
the night trained men sat and listened
to vessels going in and out of Boston
harboS. The Navy attempted, to slip
q submarine through the harbor en-
trance one night, but the craft was
detected at once and full report of
her activities was sent to headquar-
ters few hours later Not a ship
could enter or leave Boston without
being heard. In fact, so sensitive was
the instrument that trained listeners
could accurately identify a ship by
name once having heard her, the en-
gine characteristics of different ships
being plainly audible and distinctive.
Meanwhile the research laboratories
were still busy adding perfections to the
apparatus. a special station was equip
ped on the Mohawk river at S0henec-
tady. and when the river froze over and
fnterfered with the work one of the en-
gineers proceeded 10 Key West to con-
tinue investigation.
Finally, after months Of practical op-
Grafton. an instrument that was consid-
cred satisfactory was put into quantity
production at Lynn. Mass. Thousands
OF detcctors were subsequently manu-
factured there. A special representative
was then sent to Europe to keep In
touch with developments.
When the submarine detector had
been turned out in sufficient quantity
the Navy Department believed that the
allies should get the beneft OF the In
vention at once. special service party,
IN charge OF Capt. T.. n; Leigh o. the
cd to take samples Of the apparatus
abroad and test 1t under actual condi-
tions before the British admiralty. The
instrument was likewise demonstrated
10 INo cTouCn dIu lthhAIl hdNAC0s
The admiralty and the supreme war
council shortly afterward adopted the
American device and from that time on
submarine patrol work was revolution
ized.
Defensive tactics which had been en-
ployed since 1914 were now no longer
the sole reliance. The war wa4 carried
into the enemy's territory. Fighting
ships, instead OF patrolling the steam
ship lanes hooking for a stray sub to
poke its periscope above tho waves.
were augmented by submarine chasers
euuipped with listening devices and
hunted the submarine In Its UNDER water
lair.
At this time the use Of nets had proved.
q failure. U-boats had been passing
laying mine fields OF the principal Brit
ish ports, and. In general having things
pretty much their own way. The depth