CHAPTER XXVIII

THE GHASTLY HAVOC WROUGHT BY THE AIR-DEMONS

THE HORROR OF BOMB-DROPPING -- ANTI-AIRCRAFT GUNS -- KINDS OF BOMBS -- STEEL DARTS--“ARROW BULLETS” AND AERIAL TORPEDOES -- MACHINE GUNS IN AIRCRAFT -- ACCURACY IN DROPPING BOMBS.

Ten years ago the dropping of bombs from balloons was still considered an illegitimate form of warfare, involving danger to non-combatants, and was under the ban of the Geneva Convention. At the Hague Peace Conference the Germans refused to abstain from bomb-dropping, and other nations followed suit. According to the German conception of war, civilians in the theater of operations must take their chance of being killed, but must not shoot back under pain of summary execution. The horrors which this theory has added to war have proved only too real, but, so far as bomb-dropping is concerned, the reality has so far fallen short of anticipations. The great Zeppelins, capable of carrying a ton of explosives, have practically been frightened out of the air by the new anti-aircraft guns; and, except for one instance at Antwerp, bomb-dropping has been confined to aeroplanes. Now, in the first place, an aeroplane can carry only a limited weight of bombs--say, two hundred pounds; and in the second place, it is extraordinarily difficult to hit anything with them. If the airman could hover over his target and take deliberate aim, he might be more dangerous; as it is, the German airman finds a cathedral hardly a big enough mark. The British airmen, at Düsseldorf and Lake Constance, adopted a different plan from the Germans; instead of dropping bombs from a great height, they made a steep “vol piqué” down on to the target, turned sharply up again, and dropped the bomb at the moment when the plane was checked by the elevator. This plan is more dangerous, but affords a better chance of hitting.

KINDS OF BOMBS

Various kinds of bombs are used for dropping from aeroplanes. A simple pattern shown in Fig. 1 consists of a thin spherical shell of steel, containing twelve pounds of tetranitranilin, which is an explosive more powerful than melinite. The stem of the bomb, by which it is handled, has an external screw-thread, and carries a pair of vanes. While in the position shown, the bomb is harmless, but as it drops, the vanes screw themselves up to the top of the stem till they press against the stop. This, by means of a rod passing down the center of the stem, “arms” or prepares the fuse seen at the bottom of the bomb, so that it acts at the slightest touch, even on the wing of another aeroplane. The fuse effects the explosion of the burster by means of a primer of azide of lead, which causes the tetranitranilin to detonate with great violence. The whole bomb weighs twenty-two pounds, and an aeroplane usually carries six of them.

The Italians, in their campaign in Tripoli, used similar bombs, but without the special device for rendering the fuse sensitive. These were not a success, as many of them failed to explode in the desert sand, and the Arabs used to collect them and throw them into the Italian trenches at night.

STEEL DARTS

The Taube aeroplanes, when they flew over Paris, used sometimes to drop steel darts pointed at one end and flattened and feathered at the other, as shown in Fig. 2. These were put up in boxes of a hundred, so that when the box was released from its hook, it turned over and released the darts.

“ARROW BULLETS” AND AERIAL TORPEDOES

The “arrow bullet” shown in Fig. 3 is a French device; though weighing only three-quarters of an ounce, its peculiar shape enables it to acquire a high velocity, so that it will kill a man when dropped from a height of six hundred yards. An aerial torpedo carried by French aeroplanes for the destruction of Zeppelins is shown in Fig. 4; it contains a powerful charge of explosive and a fuse, to which the suspending-wire is connected. When dropped on a Zeppelin, the needle-pointed torpedo pierces the envelope and gas-chamber, but the wooden cross is arrested and the sudden jerk on the suspending-wire sets the fuse in action, causing the certain destruction of the airship. The torpedo would be too dangerous to handle, but the French have an ingenious device which renders it perfectly safe until it is dropped.

MACHINE GUNS IN AIRCRAFT

Various attempts have been made to mount machine guns on aeroplanes, but the operator, in his narrow seat, has hardly space to point a machine gun in any direction except straight to his front. The American Curtis machine gun exhibited at Olympia is the most efficient form yet produced, but at present the airman seems to prefer an automatic rifle. Even in the early days of the war, Sir John French was able to report that British airmen had disposed of no less than five of the enemy’s aircraft with this weapon.

The Zeppelins are well armed with machine guns, carrying one in each of the two cars, and one on top of the structure. Access is had to the latter by means of a shaft and ladder which passes up through the gas-chambers.

ACCURACY IN DROPPING BOMBS

The Zeppelins have elaborate bomb-dropping apparatus with which it should be theoretically possible to drop a bomb with great accuracy, but on the occasion when it was tried at Antwerp, the Germans met with no great success. The principle of the bomb-dropping device is as follows: A sort of camera, pointed vertically downwards, is used, and an observer notes the speed with which an object on the ground passes across the field, and the direction in which it appears to move. He then reads the height of the airship from the barometer, which gives the time taken by the bomb to fall, say fifteen seconds for 3,500 feet. He has now to calculate, from the data given by the camera-observation, the allowance to be made for speed and leeway for fifteen seconds of fall, and to point his sighting-tube accordingly. The air-ship is steered to windward of the target, and at the moment when the target (say, the second funnel of a dreadnaught) appears on the cross wires, the nine hundred-pound bomb is dropped, and the ship goes to the bottom.