Free trader-journal. (Ottawa, Ill.) 1916-1920, 1918-07-31
AIR RAIDERS FEAR
THE SEARcHL|GHT
Allies Find Powerful and Far
Reaching Illumination an I'm
portant Factor.
USEFUL IN SpoTT|NG TANKS
Pick Up Hun Bombing Planes at a
Distance and Keep Them Con.
stantIy in View-Equlpped
With Sound Detectors.

New YOrk.--Last fall, when the AUS
trims were driving the Italian sol
diers from their hard-won mountain
fortresses. the defeated army had one
weapon which 1t constantly used 10
hnrass and impede the foe. This was
the electric searchlight. a newcomer
on the field of battle.
Powerful lights were trained every
night upon the advancing Austrians
whenever they came to II river cross
ing or whenever they were obliged TO
halt for another reason. This ham
pered and irritated the enemy ex-
ceedingly. II was not only nat So
rious danger attended any disclosure
of their operations. They suffered
also from nerves when the long feel
ers of light brushed over their faces
and hands and revealed every detail
of the work upon which they were
engaged.
The use of searchlights by our
own expeditionary forces Is becoming
an important branch of the engineer
Ing service Not long ago congress
voted an appropriation of S10WmO
for searchllghts of both the field type
and the anti-aircraft type. The lights
commonly used are 36-inch lights. hav-
ing a candlepower Of 1,00O00O,000. and
maximum range of approximately
10000 yards, or nearly six miles.
First Use In Warfare.
When searchIights were first intro
duced In warfare II was expected that
they would he primarily service
able In battlefield Illumination. The
scheme was to throw light upon the
opposing battle line and show adj
vancing companies Of infantry the
kind of ground over which they had
70 60. Another plan was to have
rows Of searchlghts parallel with the
trenches and sweep the terrain be-
fore them. lighting up the barhed-
wire entanglements laid by the foe
and exposing parties of enemy SOL
diers ut work repairing them. How
ever, neither of these uses turned ont
to be especially significant. The diff
hculty was that as soon as the lights
were In operation, they were easily
picked OF by the enemy's guns. In
the same manner, they could not be
placed along the line Of trenches
More recent experiments have dem
onstated that there Is real useful.
ness for field searchlights. They are
now being employed to spot the en-
emy's tank advances. Instead Of be-
ing hauled by horses, like the first field
searchlghts. the newer ones are
mounted on motor trucks. They are
flashed for only a minute or two at a
time, and are instantly shifted to an
other vantage point This affords
them greater measure Of self-pro.
lection.
The antiaircraft searchlight is the
most valuable type of light now used
by our soldiers. II Is our most ef-
fective defense against the low-hying
night-bomblng plane Of the Germans.
Antialrcraft guns have proved almost
hopelessly inadequate In coping with
night air raids, and II II were not for
light the foe would he able to effect
some very deadly work In night at
tacks upon supply depots and ammuni-
tion dumps.
The method is to pick IN n hostile
bombing plane when II Is about five
miles away from its objective. For
this purpose the searchlights are To-
Gated at points likely to be attacked.
They are sunk In holes in the ground
and are heavily sandbagged. Both the
light md the men working 1t are given
considerable protection.
Fitted With Sound Receivers.
To detect the approach Of airplanes
the searchllght apparatus Is furnished
with sound receivers. Without these
receivers the outfit Is practically USE
less. The receiver can be swung
around 10 catch the sound vibrations,
and they are remarkably accurate in
discovering the position Of the plane.
Usually 1t can he located within few
degrees The light is not turned on at
all until the airplane is practically To-
Gated, Then II is suddenly flashed on
the craft. Once bombing plane Is
found It Is hard for 1t TO get away from
the memorable pencil of light. Bomb
ing planes are not Ike battle planes
they must fly In comparatively
straight lines and are not free TO
twist and turn So as TO wriggle out
Of range Of the light
The first thing an aviator does wher
he finds himself IN The spotlight is to
rise That Is Just what the operator of
the searchight wants him to do. The
higher he goes the less accurate his
aim becomes and the smaller grows
the chance that he can hur his bombs
ut a desired point Furthermore. he l.
dazzled by the light and his sense of
security Is completely destroyed. Some.
times be can he found out by one oi
the aniaircraft guns, or pursued by
one NJ our own airplanes. Even II ihe
searchlIgh' crew does nothing more
than 10 frlghten an alrman and driv,
him away II has performed defensiv,
act which may save quantities ot
stores and ammunition, 10 say nothIn.
OflIves.
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