When Stephen Montgolfier and his brother Joseph, in November, 1782, sent a sheep, a rooster, and a duck into the sky, lifted by a paper bag inflated with hot air, these Columbuses of ballooning could scarcely foresee the importance that their invention was to have in the great war 135 years later. To the humble observation balloon in France rather than to his dashing hero of a cousin, the airplane, must go the chief credit for that marvelous accuracy which long-range artillery attained during the great struggle.
The balloon itself was spectacular enough once its true character was known. The fact that the American production of observation balloons during our 19 months as a belligerent was a complete and unqualified success makes the story of ballooning in France of particular interest to the American reader.
After the animals of the Montgolfier barnyard had made their ascent, two friends of the brothers, M. Pilatre de Rozier and Girond de Villette, essayed to be the first human beings to take an aerial flight, ascending to a height of 300 feet and returning to earth sound of limb and body. Thereafter and until the great war in Europe the balloon remained the awe of the circus and country fair grounds and the delight of the handful of sportsmen who took up the adventurous pursuit; but, except for a limited use of captive balloons in our Civil War and in the siege of Paris, in 1870 and 1871, the balloon had no important military use.
The hot-air balloon never could have become of great value to armies. In the first place, it would descend when the balloon cooled off. This defect was overcome by the use of lighter-than-air gas. Moreover, the free balloon was subject to the whims of the breezes. To overcome this characteristic the balloon must be fastened by a cable or propelled by a portable engine. It was obvious, however, to military experts that a stationary observation post anchored thousands of feet in the air would be ideal in war operations; yet for all of this obvious need, until the great war military science had perfected nothing better than the spherical balloon. The spherical, anchored to a cable, bobbed aloft in the gales and zephyrs as a cork does on the ocean waves. Although there had been some experimentation with kite balloons before 1914, it was not until the great war had been in progress for some months that the principles of streamline shape were applied to the captive balloon; and the kite balloon, the well-known "sausage," made its appearance, to be the target for enemy aerial operations and the chief dependence of its own Artillery.
The term "kite balloon" effectively describes the captive observation balloon as we knew it in the war. It rides the air on the end of its cable much in the manner of an ordinary kite, and some of the early "sausages" even flaunted steadying tails such as kites carry. These principles applied to the captive balloon gave to its observation basket a stability unknown by the pioneer aeronauts under their spherical bags.
In the first stages of the war the Artillery relied principally upon airplanes for firing directions. But, while the airplane observers could locate the targets fairly well, they frequently lost touch with their batteries because of the difficulty of sending and receiving wireless or visual signals upon their swiftly moving craft. This disadvantage brought the captive balloon into use, gradually at first, but before the end of the war on a scale which had practically displaced the airplane as a director of gun fire. The balloon came to be the very eye of the Artillery, which, thanks to the development of this apparatus, reciprocated with an efficiency beyond anything known before in the history of warfare.
Sitting comfortably aloft, the observer in the kite balloon basket had the whole panorama of his particular station spread before him. His powerful glasses could note accurately everything transpiring in a radius of 10 miles or more. He was constantly in touch with his batteries by telephone and not only could give by coordinated maps the exact location of the target and the effect of the bursting shell, but could and often did supply most valuable information of enemy troop movements, airplane attacks, and the like. He was a sentinel of the sky with the keen, long-range vision of the hawk. He played a part less spectacular than the scout airplane with its free and dazzling flights, but his duties were not less important.
Nor did he suffer from ennui during his period aloft. When a kite balloon went up it became the subject of alert attention by the enemy, because it was up there on hostile and damaging business. Long-range high-velocity guns turned their muzzles on it, and planes swooped down upon it from dizzy heights, seeking to pass through the barrier of shell from antiaircraft guns and get an incendiary bullet through the fabric of the gas bag, an eventuality which meant the ignition of the highly inflammable hydrogen gas, the quick destruction of the balloon and perhaps of the luckless occupants of the basket as well, unless they could get away in their parachutes.
Only quick work could save the men in the basket in such a case. From the time the gas leaped into flame until the explosion and fall of the balloon there was an interval of rarely over 15 or 20 seconds. The pilot of the airplane could dodge and slip away from the guns, but not so the pilot of the kite balloon anchored to a windlass from 2 to 5 miles behind his own lines. He had to take what was coming to him without means of defense. He must carry on his scientific calculations unconcernedly and in his spare moments experience the questionable pleasure of watching on some distant hill the flash of an enemy gun trained upon him and then of waiting the 20 or 30 seconds for the whizzing messenger to reach him, the while he pondered on the accuracy of the enemy gunner's aim.
While the artillery on both sides paid considerable attention to the observation balloons, the fact was that few of them were brought down by direct shell hits. The diving airplane with its incendiary bullets was a far more deadly enemy to the balloon than the ground artillery. Certain pilots in all the air services made a specialty of hunting sausages, the nickname given to kite balloons because of their shape. In the 17 days between September 26 and November 11, 1918, our Army lost 21 balloons, of which 15 were destroyed by enemy planes and 6 by enemy shell. But it may be noted that our aviators and artillery exacted a toll of 50 German balloons in the same period and on the same front. Of 100 balloons lost at the front, an average of 65 were destroyed by enemy attacks and 35 by natural wear and tear.