This is all the more surprising when America’s previous backwardness in aviation is considered. This country has stood practically still in aerial progress, while the war in Europe brought about an extraordinary advance. From all this the United States was entirely shut off up to the time it abandoned neutrality. So little exact knowledge was available that the first American planes to go with the expedition into Mexico in March, 1916, were all rendered useless in accidents within a short time of arrival. There was practically no aviation technique here comparable to Europe’s, almost negligible manufacturing facilities, not a hundred trained flyers, and only the most rudimentary facilities for training. Moreover, no one had any adequate appreciation of the intricacy and skill required in the making of either an aeroplane or the training of a pilot. As against this stagnation Europe’s progress in two and one-half years of war had been tremendous. The first planes to go to the front in 1914 had been few in number, unequipped with radio, machine guns, bombs, or photographic apparatus, and entirely unproved in military value. Their extraordinary success, however, in disclosing the size of the German concentration in Belgium at once brought them into a position of great importance. Very shortly radio was installed to replace signaling by dropping tinsel or making curious evolutions; the pistols of the pilots gave way to machine guns; the easy-going system of dropping bombs over the side was replaced by regular bombing planes, and the occasional taking of photographs by an intricate system of picturing every mile of the front. Engine power increased to 200, 300, 400, 500 horse power; huge planes with large carrying capacity were being developed for night-bombing; and operations were taking place by whole squadrons in various air strata—light, single-seater scouts around 15,000 to 20,000 feet, two-seater day bombers around 9,000 feet, and photographic and observation planes around 6,000 feet. In contrast to all this development the United States at the time of its entry into the war stood very little ahead of where it had been before the world war broke out. Aviation, both in its personnel and its equipment, was included in that part of the Signal Corps known as the Aviation Section, which had been established by Congress July 18, 1914. Its chief was Maj. Gen. George O. Squier, who after four years as military attaché in London, had been put in charge of the Aviation Section in May, 1916, and made Chief Signal Officer on February 14, 1917, continuing to have charge of aviation through nearly the whole of the fiscal year. On April 6, 1917, the total assets on hand consisted of 65 officers, 1,120 men, two small flying fields, less than 300 very second-rate training planes, practically no manufacturing facilities, and only the most meagre technical information as to Europe’s startling developments.