© U. & U.
The Balloon from which the Aviators Fled.
It may be properly noted at this point that the captive balloons or kite balloons have proved of the greatest value for observations in this war. Lacking of course the mobility of the swiftly moving airplanes, they have the advantage over the latter of being at all times in direct communication by telephone with the ground and being able to carry quite heavy scientific instruments for the more accurate mapping out of such territory as comes within their sphere of observation. They are not easy to destroy by artillery fire, for the continual swaying of the balloon before the wind perplexes gunners in their aim. At a height of six hundred feet, a normal observation post, the horizon is nearly thirty miles from the observer. In flat countries like Flanders, or at sea where the balloon may be sent up from the deck of a ship, this gives an outlook of the greatest advantage to the army or fleet relying upon the balloon for its observations of the enemy's dispositions.
Most of the British and French observation balloons have been of the old-fashioned spherical form which officers in those services find sufficiently effective. The Germans, however, claimed that a balloon might be devised which would not be so very unstable in gusty weather. Out of this belief grew the Parseval-Siegfeld balloon which from its form took the name of the Sausage. In fact its appearance far from being terrifying suggests not only that particular edible, but a large dill pickle floating awkwardly in the air. In order to keep the balloon always pointed into the teeth of the wind there is attached to one end of it a large surrounding bag hanging from the lower half of the main envelope. One end of this, the end facing forward, is left open and into this the wind blows, steadying the whole structure after the fashion of the tail of a kite. The effect is somewhat grotesque 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 aërial 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 to estimate the military value of these exploits. Merely to inflict anguish and death upon a great number of civilians, and those largely women and children, is obviously of no military service. But if such suffering is inflicted in the course of an attack which promises the destruction or even the crippling of works of military character like arsenals, munition plants, or naval stores, it must be accepted as an incident of legitimate warfare. The limited information obtainable in wartime seems to indicate that the German raids had no legitimate objective in view but were undertaken for the mere purpose of frightfulness.
The methods of defence employed in Great Britain, where all attacks must come from the sea, were mainly naval. What might be called the outer, or flying, defences consisted of fast armed fighting seaplanes and dirigibles. Stationed on the coast and ready on the receipt of a wireless warning from scouts, either aërial or naval, that an enemy air flotilla was approaching the coast, they could at once fly forth and give it battle. A thorough defence of the British territory demanded that the enemy should be driven back before reaching the land. Once over British territory the projectiles discharged whether by friend or foe did equal harm to the people on the ground below. Accordingly every endeavour was made to meet and beat the raiders before they had passed the barrier of sea. Beside the flying defences there were the floating defences. Anti-aircraft guns were mounted on different types of ships stationed far out from the shore and ever on the watch. But these latter were of comparatively little avail, for flying over the Channel or the North Sea the invaders naturally flew at a great height. They had no targets there to seek, steered by their compasses, and were entirely indifferent to the prospect beneath them. Moreover anti-aircraft guns, hard to train effectively from an immovable mount, were particularly untrustworthy when fired from the deck of a rolling and tossing ship in the turbulent Channel.
Third in the list of defences of the British coast, or of any other coast which may at any time be threatened with an aërial raid, are defensive stations equipped not only with anti-aircraft guns and searchlights but with batteries of strange new scientific instruments like the "listening towers," equipped with huge microphones to magnify the sound of the motors of approaching aircraft so that they would be heard long before they could be seen, range finders, and other devices for the purpose of gauging the distance and fixing the direction of an approaching enemy.
Some brief attention may here be given to the various types of anti-aircraft guns. These differ very materially in type and weight in the different belligerent armies and navies. They have but one quality in common, namely that they are most disappointing in the results attained. Mr. F. W. Lancaster, the foremost British authority on aircraft, says on this subject: