[Illustration: FIG. 89.--Travelling workshop for the repair of military aeroplanes.] It seems likely that the air-fleet of the future will be composed of craft of many types. There will be the long-distance scout--a machine capable of flying for many hours at moderate speed and surveying wide tracts of country. Then there will be a flotilla of very fast, single-seated machines, used for a dash above an enemy’s force. These high-speed scouts will run the gauntlet of the enemy’s destroyers, rushing into the danger zone and sweeping out again, rather like a torpedo-boat in naval war. Then there will be the fighting squadron--machines armoured and carrying powerful guns, which will fight the enemy’s war-planes and give battle to hostile airships; and there may be a further type of destructive plane for use against the forces on land. This would be a machine well armoured, with its motors silenced, and perhaps with transparent wings. It would steal upon ammunition parks and supply trains, firing with its guns and raining down bombs; and such a craft would be used, also, to seek and attack the aircraft stations of the enemy. These would be protected, of course, by high-angle guns and patrol planes. Immense damage might be wrought by bombs were hostile craft to discover, and attack without resistance, a squadron of machines in their sheds. [Illustration: _Photo, Topical._ PLATE XIII.--AN AEROPLANE FACTORY. In this picture, which shows one of the workshops at Hendon, the wooden framework of a main-plane is seen in the foreground; and at the rear of the shop is the hull and centre wing-section of a biplane.] A machine which does not exist now, but which may be built before long, is an aeroplane transport for troops. This would be a very large craft, built entirely for weight-lifting. It would raise a load of say ten or more men; and such machines would be held in readiness so that a relief column could be embarked in them and carried at high speed to some point, perhaps a number of miles distant, at which reinforcements were needed urgently. Could such aeroplane transport be organised, and handled with success, it might be of the highest value during a battle. If a thousand machines were built, each carrying ten men, and they made three flights to some given spot, a force of 30,000 men could be transported by air; and even with a slow-flying, weight-carrying machine, a distance of say 30 miles should be transversed in half-an-hour. Battles have been won by virtue of forced marches, thus bringing troops to some vantage-point before an enemy expects them. Napoleon, for example, was a master of such quickly-delivered blows. Day and night, on many occasions, he hurried his tired troops across country; and what would he have given to embark a column upon aeroplanes, and send them high over hills and forests at the speed of an express train?