rd the "Archies" is one of
calm contempt.

The German mind being distinctly scientific invented early in the
war a method of fixing the range and position of an enemy airplane
which would be most effective if the target were not continually in
erratic motion. The method was to arrange anti-aircraft guns in a
triangle, all in telephonic connection with a central observer. When
a flyer enters the territory which these guns are guarding, the
gunner at one of the apexes of the triangle fires a shell which
gives out a red cloud of smoke. Perhaps it falls short. The central
observer notes the result and orders a second gun to fire. Instantly
a gunner at another apex fires again, this time a shell giving
forth black smoke. This shell discharged with the warning given by
the earlier one is likely to come nearer the target, but at any rate
marks another point at which it has been missed. Between the two a
third gunner instantly corrects his aim by the results of the first
two shots. His shell gives out a yellow smoke. The observer then
figures from the positions of the three guns the lines of a
triangular cone at the apex of which the target should be. Sometimes
science wins, often enough for the Germans to cling to the system.
But more often the shrewd aviator defeats science by his swift and
eccentric changes of his line of flight.

At the beginning of the war Germany was very much better equipped
with anti-aircraft guns than any of her enemies. This was due to the
remarkable foresight of the great munition makers, Krupp and
Ehrhardt, who began experimenting with anti-aircraft guns before the
aircraft themselves were much more than experiments. The problem was
no easy one. The gun had to be light, mobile, and often mounted on
an automobile so as to be swiftly transferred from place to place in
pursuit of raiders. It was vital that it should be so mounted as to
be speedily trained to any position vertical or horizontal. As a
result the type determined upon was mounted on a pedestal fixed to
the chassis of an automobile or to the deck of a ship in case it was
to be used in naval warfare. The heaviest gun manufactured in
Germany was of 4-1/4-inch calibre, throwing a shell of forty pounds
weight. This could be mounted directly over the rear axle of a heavy
motor truck. To protect the structure of the car from the shock of
the recoil these guns are of course equipped with hydraulic or other
appliances for taking it up. They are