Swinging lazily above the field was a captive balloon. At one end of Le Bourget was a line of waiting airplanes. "This is the second; they have already brought down one balloon," remarked the man at my elbow. The hum of a motor caused me to look up. A wide-winged double motor, Caudron, had left the ground and was mounting gracefully above us. Up and up it went, describing a great circle, until it faced the balloon. Everyone caught his breath. The Caudron was rushing straight at the balloon, diving for the attack.
"Now!" cried the crowd. There was a loud crack, a flash, and eight long rockets darted forth leaving behind a fiery trail. The aviator's aim however was wide, and to the disappointment of everyone the darts fell harmlessly to the ground.
Another motor roared far down the field, and a tiny appareil de chasse shot upward like a swallow. "A Nieuport," shouted the crowd as one voice. Eager to atone for his copain's failure, and impatient at his delay in getting out of the way, the tiny biplane tossed and tumbled about in the air like a clown in the circus ring.
"Look! he's looping! he falls! he slips! no, he rights again!" cried a hundred voices as the skilful pilot kept our nerves on edge.
Suddenly he darted into position and for a second hovered uncertain. Then with a dive like that of a dragon-fly, he rushed down to the attack. Again a sheet of flame and a shower of sparks. This time the balloon sagged. The flames crept slowly around its silken envelope. " Touchez!" cried the multitude. Then the balloon burst and fell to the ground a mass of flames. High above the little Nieuport saucily continued its pranks, as though contemptuous of such easy prey.
[Illustration: Aviators Descending in Parachutes from a Balloon Struck by Incendiary Shells. © U. & U.]
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.
[Illustration: The Balloon from which the Aviators Fled. © U. & U.]
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.
