tesque as anyone who has studied the numerous
pictures of balloons of this type employed during the war must have
observed. It looks not unlike some form of tumor growing from a
healthy structure.

Captive or kite balloons are especially effective as coast guards.
Posted fifty miles apart along a threatened coast they can keep a
steady watch over the sea for more than twenty-five miles toward the
horizon. With their telephonic connections they can notify airplanes
in waiting, or for that matter swift destroyers, of any suspicious
sight in the distance, and secure an immediate investigation which
will perhaps result in the defeat of some attempted raid. Requiring
little power for raising and lowering them and few men for their
operation, they form a method of standing sentry guard at a nation's
front door which can probably be equalled by no other device. The
United States at the moment of the preparation of this book is
virtually without any balloons of this type--the first one of any
pretensions having been tested in the summer of 1917.

As late as the third year of the war it could not be said that the
possibilities of aerial offense had been thoroughly developed by any
nation. The Germans indeed had done more than any of the
belligerents in this direction with their raids on the British coast
and on London. But, as already pointed out, these raids as serious
attacks on strategic positions were mere failures. Advocates of the
increased employment of aircraft in this fashion insist that the
military value to Germany of the raids lay not so much in the
possibility of doing damage of military importance but rather in the
fact that the possibility of repeated and more effective raids
compelled Great Britain to keep at home a force of thirty thousand
to fifty thousand men constantly on guard, who but for this menace
would have been employed on the battlefields of France. In this
argument there is a measure of plausibility. Indeed between January,
1915, and June 13, 1917, the Germans made twenty-three disastrous
raids upon England, killing more than seven hundred persons and
injuring nearly twice as many. The amount of damage to property has
never been reported nor is it possible to estimate the extent of
injury inflicted upon works of a military character. The extreme
secrecy with which Great Britain, in common with the other
belligerents, has enveloped operations of this character makes it
impossible at this early day