3802 UNIVERSAL HISTORY-THE MODERN WORLD.
to prearranged plans. One of the
pioneers in developing such fighting was the
German Baron von Richthofen, whose "flying circus" became famous. This squadron
flew in a circle, each plane being supposed
to protect the rear of the plane before it.
Aeroplanes were also beginning to perform
good service in assisting infantry attacks,
both with bombs and machine guns. Thus
in the attack upon the Chemin des Dames,
in October, the French airmen flew as low as
a hundred yards and sprayed German
infantry with showers of bullets. All the
aeroplanes taking part in the battle were
riddled with bullets. One fell blazing among
advancing French troops, but the pilot was
uninjured and joined the nearest battalion.
Aeroplanes were put to many services and
proved far more useful than Zeppelins, but
even they had decided limitations. To the
end of the war, the damage done by their
bombs was smaller than was generally supposed. They were helpful for photographic
and reconnaissance work. But the improvement of aerial defense methods forced planes
to keep higher and higher in the air, and they
frequently failed to give warning of large
troop concentrations, as was clearly shown
by the success of the British and German
surprises near Cambrai and by the Teutonic
attack on Italy. Camouflaged batteries
frequently deceived the eyes of aeroplane
observers and even those of their cameras.
Stationary balloons were more and more
used by all armies for reconnaissance work,
while some other very interesting methods
were employed to locate the enemy's guns.
One of these methods was known as "flash
spotting," and consisted in plotting the
position of a gun by observing the flash of
its shots. A still more ingenious method was
to locate a gun's position by means of a study
of sound waves. In the last year of the war,
Allied machines were perfected whereby the
position of a cannon could thus be determined within a few yards.