GETTING THE OBSERVER OFF THE GROUND
This was the method of getting the range in previous wars and it was used to a considerable extent in the war we have just been through. But the great European conflict brought out wonderful improvements in all branches of fighting; and range-finding was absolutely revolutionized, because shelling was done at greater ranges than ever before, but chiefly because the war was carried up into the sky.
A bird's-eye observation is much more accurate than any that can be obtained from the ground. Even before this war, some observations were taken by sending a man up in a kite, particularly a kite towed from a ship, and even as far back as the Civil War captive balloons were used to raise an observer to a good height above the ground. They were the ordinary round balloons, but the observation balloon of to-day is a very different-looking object. It is a sausage-shaped gas-bag that is held on a slant to the wind like a kite, so that the wind helps to hold it up. To keep it head-on to the wind, there is a big air-bag that curls around the lower end of the sausage. This acts like a rudder, and steadies the balloon. Some balloons have a tail consisting of a series of cone-shaped cups strung on a cable. A kite balloon will ride steadily in a wind that would dash a common round balloon in all directions. Observers in these kite balloons are provided with telephone instruments by which they can communicate instantly with the battery whose fire they are directing. But a kite balloon is a helpless object; it cannot fight the enemy. The hydrogen gas that holds it up will burn furiously if set on fire. In the war an enemy airplane had merely to drop a bomb upon it or fire an incendiary bullet into it, and the balloon would go up in smoke. Nothing could save it, once it took fire, and all the observers could do was to jump for their lives as soon as they saw the enemy close by. They always had parachutes strapped to them, so they could leap without an instant's delay in case of sudden danger. At the very first approach of an enemy airplane, the kite balloon had to be hauled down or it would surely be destroyed, and so kite balloons were not very dependable observation stations for the side which did not control the air.
As stated in the preceding chapter, just before the fighting came to an end, our army was preparing to use balloons that were not afraid of flaming bullets, because they were to be filled with a gas that would not burn.