Before the present type of reconnaissance craft, bristling with machine guns had been developed, it was customary for the airplane doing photographic work, artillery “spotting” and similar duties to rely for its protection on a number of speed scouts, who flew above and around it and escorted it upon its mission. To-day the airplane that is used for general service duties over the lines is a dreadnaught of the air, and although it may still take along with it on its errands a few scouts to give battle to the faster airplanes of the enemy, yet on the whole it is self-reliant and has little to fear.

To these slower-flying, larger general service machines are entrusted some of the gravest duties of war. They are the eyes of the army, whether they act for the heads of staff, flying out over the territory of the foe with their trained observers and bringing back accurate information about the movements of troops, whether they help in “spotting” targets for the gunners, or whether during an actual engagement they act as aerial spectators and messengers, helping to coordinate the efforts of the various bodies of troops.

From the beginning of hostilities Germany strove to overwhelm the French in the air and prevent their airplanes from performing these necessary duties. France was at first but poorly equipped with machines of the type so sorely needed to maintain her air supremacy. By the skill and bravery of her airmen she managed to hold out, however, and the Huns were disappointed in never accomplishing their purpose of putting out her eyes. Her engineers were in the long run much more clever than those of Germany, and by the early part of 1915 they had ready a number of superior machines for reconnaissance and bombing. For the most part they were big Caudrons and Farmans, well armed and a good match for the German maid-of-all-work biplanes. And there were large Voisin biplanes, suitable for photographic work or for bombing. They were used extensively by French, British, Belgians and Italians. The Voisin, as in its very earliest models, is still easily recognizable by its curious tail resembling a box-kite, placed at the end of a projecting framework of four long beams or outriggers. It is a pusher type of airplane, with its propeller at the stern instead of at the bow.

Larger and more formidable grow the “aerial destroyers.” To-day among the super-dreadnaughts of the sky may be numbered the big biplanes bearing the names of Moineau, Breguet-Michelin, Voisin-Peugeot, and Farman. Heavily armed with machine guns they rendered valuable service to the Allies in many capacities, and they were the efficient answer to the struggle of the Hun for aerial supremacy. When in the Spring of 1918 the Germans launched their tremendous offensive at the Allies, the latter were well informed in advance of their intentions, thanks to these powerful reconnaissance planes. Swooping down close to the German lines in defiance of anti-aircraft guns and fighting machines alike, they had daily looked on at the massing of troops, the bringing up of reenforcements for the drive, and the piling up of ammunition supplies. In spite of every effort of the enemy to make their mission an intolerable one and to prevent them from spying upon preparations for the offensive, they had succeeded in bringing back to Allied commanders accurate and detailed information. By their aid the Allies knew at what points to expect the heaviest blows, and there they collected their reenforcements. Thus the nations lined up against the Hun were ready when the blow came, and they were able to check the tremendous onslaught by their land and air forces. What they really lacked perhaps, was not “eyes,” to discover what the Germans were plotting, but a large enough number of small fighting machines to keep the enemy reconnaissance craft from spying upon their own preparations; and a large enough number of huge bombing planes to have completely interfered with the German efforts to mass reenforcements and ammunition for the push.

In the long run it is perhaps the bombing plane that represents the greatest saving in human life in time of war. An army may be well equipped with reconnaissance machines and speed scouts, so that it may keep in closest touch with every move of the enemy. But unless it is able to interfere with those moves before they reach the proportions of a direct and staggering blow, then the best it can do is to concentrate its own troops and supplies in readiness to meet the blow when it does fall. That means that hundreds of thousands of lives of infantrymen will be sacrificed in checking the waves of enemy troops.

The Allies discovered a far better and more economical way of winning the war than this, and in the last year of the War they strained every nerve to put it into actual operation. It was this: to search out every military base of the enemy, every munition dump, nest of guns, supply train or troop train and drop bombs upon it. Two men in a bombing machine can attack and perhaps destroy a force which, if allowed to reach the front lines, would have to be met by several thousand infantrymen. Two men in a bombing machine can destroy at a single blow the ammunition which, if it had reached the front, might have swept out a regiment.

That is why so much thought and genius has been expended upon the bombing plane. The day bomber becomes the right arm of the infantry, flying low over the lines, attacking troops and striking terror to the heart of the enemy as the huge Allied tanks did when they first started on their irresistible slow walk across trenches, troops, buildings and every manner of obstruction. The big bomber—particularly if the fighting machines have cleared the way ahead of it—is something like that: it is an invincible weapon of destruction, wiping out whole bodies of the foe at every stroke, like a giant sweeping the pigmies of earth ahead of him with his strong right arm.

The big dreadnaughts of the air like the Moineau, the Voisin-Peugeot, the Breguet, and the Farman, become, when a bombing apparatus is substituted for their camera and radio, very efficient day bombers. There is a long list of others: as for instance, the British Avro, Handley-Page and Sopwith machines and the French Caudron, Dorand and Letord.

Many of these big bombing planes were designed for long distance work either by day or by night, and so they have been made enormous weight-lifters, with large supporting surfaces, two or more engines, and equipped with a fuel supply sufficient for long runs. In order to carry their engines conveniently they very often have more than one fuselage. Sometimes the pilot sits in a large fuselage in the center, while the motors are carried in two smaller cars or bodies called “nacelles” at either side. The British Avro, for instance, is a huge biplane with three fuselages and two rotary engines. Its upper and lower wings are equal in span, and it can readily be distinguished from the British Handley-Page, whose upper wing has a large overhang. The Handley-Page is one of the largest machines built. It carries its two 12-cylinder Rolls-Royce engines in small nacelles between the main planes, and it can be recognized by these and its biplane tail.

The Caudron is another big twin-motored machine, used by French, British and Italians. Its two rotary engines are fixed in small nacelles between the planes, while the pilot rides in a center fuselage. Somewhat after the manner of the Voisin, it carries its tail at the end of a projecting framework of four long beams, the lower two of which act also as landing skids.