The Washington times., 1923-05-31
COUNTRY MADE
SAFE FROM
ATTACK
Anti-Aircraft Improvement Is
Keeping Pace With Improve
ment of Planes.
BY GEORGE e. DURNO.
Copyright, 1923, by International
News Service.)

Of aviation, other branches Of the
army and navy have not remained
idle. Working quietly, but efficient
ly, the Coast Artillery, the Ord
nance Department, the Chemical
Warfare Service, and corresponding
branches of the navy, have evolved
q system of defense against that
very development which will render
American sea coasts and cities
impregnable to attack by air.
Anti-aircraft development, Inter
national News Service learned to-
day, has kept pace. step by step.
with the rise Of aviation since the
war and there Is no great improve
ment in the airplane as an offensive
weapon that has not been matched
and offset by defensive strategy.
Aided by remarkable new inven-
tons and improvements, series or
defense plans have been worked out
for the protection of the entire
country.
Three New Guns Perfected.
Outstanding among the latest ad-
ditions to anti-aircraft defense, and
hitherto undisclosed, are:
An anti-aircraft gun firing q
shell At inches in diameter, with
velocity more than two times
greater than the French Is nm.
used during the war.
A 81 MN. Il hinch) machine gun
now in the course Of completion.
A so canber machine gum the
outgrowth Of the 80 caliber gun
used during the war.
A tracer bullet visible to the
naked eye to a height Of 1000
feet.
A sounder capable of warning
against oncoming airplanes. CIV
ing their direction and location
with almost exact accuracy.
A plan OF safeguarding highly
important points. such as canal
locks, arsenals, etc., against bomb
ing by the use of huge nets car
ried into position by balloons.
which is now in the course or
completion.
A gas defensive to be used
should any other nation be so
barbaric" as to resort to that
forbidden weapon OF war.
All of the foregoing developments
either have been fully and success
fully tested or have been developed
to q point where success appears to
be assured. Tests are now in prog
ress at the Aberdeen, Md, proving
grounds and at Fortress Monroe. Va.
Keep Planes at 10000 Feet.
The theory Of defense against air.
craft during the war was to keep
the invading planes at height OF
10, 900 feet. The present theory, as
explained by army experts, is not
only to keep them at that height
but also to injure and disband
them. This theory has been accom-
plished by concentration on greater
velocity and bursting radius and all
of the new guns have proven equal
to the new standard.
During the war the French
75-mm. and the three-inch gun were
used exclusively, the latter only in
the final stages. Figures compiled
show that the French used approx.
mately 5000 shells to bring down
one airplane, while the American
forces used 500.
Against this is the recent expert.
ment in which a kite equal in size
to a plane was lowed TOO yards be-
hind a plane at a height Of 1000
feet and was completely riddled with
bullets from a .60-caliber machine
gun.
During the war, German air raids
on Paris and London were feared
greatly, and no inkling of the pres
ence Of the enemy planes was given
until Immediately before actual
bombing commenced.
With the new type Of sounder,
no plane has been able to "sneak
in" on Fortress Monroe. though
many have tried, while a sounder
located at the Army War College
here picked up and located instantly
gun fired on the Monument
grounds, distance Of about three
miles.
The great advantage In the three
new guns-the Al and the 80
caliber and 81 nm. machine guns
lie in their greatly increased
velocity, greater bursting radius
whereas the wartime "75" Travelled
L, TT
goes at a rate of 1000 feet. This
enables almost direct firing, which
the tracer bullets would facilitate
to a height of 1000 feet, while with
bursting radius five times greater
than that attained during the war
an almost impossible barrage
would be laid down. All of these
gun are highly flexible and mobile
while the idea Of a machine gun
firing shells one and one half inches
in diameter, as in the case of the
new 81 nm, army officials believe
will do much to break the morale
of any attacking force.
Gas Only for Retaliation.
Gas-tabooed under the arms con
ference treaties-would be resorted
to only in retaliation, but even in
this exigency the United States is
prepared. Recent developments make
possible the concentration of any
known gas into liquid form to be
projected into the air and exploded
there and form an invisible clouC
almost impossible.
The idea of utilizing huge nets
suspended by balloons to protect
vulnerable points, while still in the
infant stage, and regardless Of the
apparent impractical ility, neverthe
less Is declared by army officials tC
be at least partially successful. Or
the sound assumption that air raids
these nets would be elevated over
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