America's beginnings in the air service were pretty closely kin to her other beginnings--she furnished the men and took over the apparatus. And although by September 1, 1917, she had large numbers of aviators in the making in France, they were flying--or aspiring to--in French schools, under American supervision, with French machines and French instructors. There existed, in prospect, and already in detailed design, several enormous flying-fields, to be built and equipped by America, as well as half a dozen big repair-shops, and one gigantic combination repair-shop, assembling-shop, and manufacturing plant. But in the autumn, when there were aviators waiting in France to go up that very day, there was no waiting on fields trimmed by America. When the main school, under American supervision, had filled to overflowing, the remaining probationers were scattered among the French schools under French supervision. Meanwhile, the engineers and stevedores shared the work of constructing "the largest aviation-field in the world" in central France. It was once true of complete armies that they could be trained to warfare in their own home fields, and then sent to whatever part of the world happened to be in dispute, and they required no more additional furbishing up than a short rest from the journey. That is no longer true of anything about an army except the air service, and it isn't literally true of them. But they approach it. So it was practicable to give the American aviators nine-tenths of their training at home, and leave the merest frills to a few spare days in France. This, of course, takes no account of the first weeks at the battle-front, which are only nominally training, since in the course of them a flier may well have to battle for his life, and often does catch a German, if he chances on one as untutored as himself. The French estimate of the necessary time to make an aviator is about four months before he goes up on the line, and about four months in patrol, on the line, before he is a thoroughly capable handler of a battle-plane. They cap that by saying that an aviator is born, not made, anyway, and that "all generalizations about them are untrue, including this one." The air policy of France, however, was in a state of great fluidity at this time. They were not prepared to lay down the law, because they were in the very act of giving up their own romantic, adventurous system of single-man combat, and were borrowing the German system of squadron formation. They were reluctant enough to accept it, let alone acknowledge their debt to the Germans. But the old knight-errantry of the air could not hold up against the new mass attacks. And the French are nothing if not practical. Even their early war aviators had prudence dinned into them--that prudence which does not mean a niggardliness of fighting spirit, but rather an abstaining from foolhardiness.