© U. & U.

At a United States Training Camp.

It is a curious fact that not long after these arrows first made their appearance in the French machines, they were imitated by the Germans, but the German darts had stamped upon them the words: "Made in Germany, but invented by the French."

© U. & U.

A "Blimp" with Gun Mounted on Top.

One of the duties of the fighting airmen is to destroy the observation balloons which float in great numbers over both the lines tugging lazily at the ropes by which they are held captive while the observers perched in their baskets communicate the results of their observations by telephone to staff officers at a considerable distance. These balloons are usually anchored far enough back of their own lines to be safe from the ordinary artillery fire of their enemies. They were therefore fair game for the mosquitoes of the air. But they were not readily destroyed by such artillery as could be mounted on an ordinary airplane. Bullets from the machine-guns were too small to make any rents in the envelope that would affect its stability. Even if incendiary they could not carry a sufficiently heavy charge to affect so large a body. The skin of the "sausages," as the balloons were commonly called from their shape, was too soft to offer sufficient resistance to explode a shell of any size. The war was pretty well under way before the precise weapon needed for their destruction was discovered. This proved to be a large rocket of which eight were carried on an airplane, four on each side. They were discharged by powerful springs and a mechanism started which ignited them as soon as they had left the airplane behind. The head of each rocket was of pointed steel, very sharp and heavy enough to pierce the balloon skin. Winslow was fortunate enough to be present when the first test of this weapon was made. In his book, With the French Flying Corps, he thus tells the story: