The machines used for directing artillery fire are bigger, and carry one or more observers as well as the pilot. They usually have two motors, so that they can still fly if one of them is put out of action. For making raids still bigger machines are used. In 1915 the French pinned their faith to a giant triplane, which well deserved to be called "the Dreadnought of the Air." It was 63 feet from wing to wing; it was driven by four powerful motors, carried two quick-firing cannon and four machine guns, as well as 1,200 pounds of explosives, and on a raid was manned by a crew of four men. You have frequently read in these pages of the scouting work done by aeroplanes. When they fly over the enemy's lines they have huge cameras fitted to the bodies of the machines. Exposures are made, and the machine speeds back to its own lines, usually amid a storm of bursting shrapnel. Every aerodrome has a dark room in which the plates are developed. An enlargement is made, and the staff is thus provided with a picture of the German trenches as seen from above. If a good photograph is taken, the positions appear as clear as daylight; even the barbed wire and the situation and number of the machine guns can be seen. Poor photographs, however, do not show the details, and cannot distinguish a trench from a watercourse. Sometimes large kites are used for photographic purposes. You can easily understand what a great change the aeroplane has produced in warfare when I tell you that during the Russo-Japanese War the Japanese fought for weeks, and sacrificed thousands of men, in order to capture the top of a hill from which their observers could overlook Port Arthur. Nowadays an aeroplane can supply all the information needed in a single hour, and howitzers can be directed from the air so that their shells will drop on the required position, though the gunners cannot possibly see their targets. A modern general would be almost lost without his air service. From dawn to dark aircraft hover over the enemy's position, photographing his trenches, "spotting" his batteries, noticing the movement of troops and trains, and bringing back priceless information. More than once French aeroplanes have landed spies behind the German lines, and have returned to pick them up again days later.