the airplane could have been found in the building with the great white dome which stands at the far end of Pennsylvania Avenue. As a direct consequence of our systematic discouragement of airplane development, when we entered the war there was no such thing as an aviation industry in the United States and the number of aeronautical engineers and designers was so small as to be practically negligible. In this respect the problem of developing an air-fleet was unique. The United States had built ships before, it had manufactured cannon, rifles, ammunition, it had fed and clothed and housed armies, and it had at its command thousands of men qualified to do these things and do them well, but, barring a handful of experts in Dayton and Buffalo, there was no one in this country with experience in the designing or building of either training or fighting planes. In short, the government was faced with the problem not merely of developing a new industry, but of _creating_ it. * * * * * In April, 1917, there were being built in the United States only four makes of aircraft engines that were sufficiently developed to be of any military value, and even these were useful only for primary training. We had no engines suited for service on the battle-front, or, indeed, even for the advanced training of pilots. Though the largest engine manufactured in the United States at this time developed about 220 horse-power, it had not measured up to the exacting requirements of combat. The other American-built engines ranged from 90 to 135 horse-power. It being evident, therefore, that the existing American engines could be used only for purposes of preliminary instruction, it was accordingly decided that their further manufacture should be limited to the training requirements. As a result of this decision, by far the greater part of the primary training of pilots has been conducted with the Curtis 90 horse-power engine, a quantity production of which was obtained early in the war, this engine being particularly valuable owing to the very satisfactory training-plane which had been designed around it. Considerable use was also made of the Hall-Scott 100 horse-power engine until the Curtiss motor could be manufactured in sufficient numbers to meet all demands for primary training. Two European engines, the Gnome 100 horse-power and the Hispano-Suiza 150 horse-power, were also being put into production in the United States at this time. These engines represented the highest product of European design and engineering skill, and were in a perfected and standardized state, at least according to European ideas, when their manufacture was undertaken in this country. But the changes involved in adapting them to manufacture by American methods required so much time, and the advances made in aeronautical engineering were so rapid, that before they could be produced in sufficient numbers they were almost obsolete for service on the front.