In one respect we were in a degree prepared in professional skill and mechanical equipment to go ahead on broad lines. This was in the matter of producing engines. The production of aviation engines in America had, indeed, been comparatively slight, but in the automobile industry had been developed a vast engine-building capacity. The detail equipment of automobile shops was not entirely suited to aviation engines, but, nevertheless, it furnished the basis for the future successful production of the Liberty engine and the other engines called for by the air program. [Illustration: 250 AIRPLANES IN THE AIR AT ONE TIME OVER SAN DIEGO, CALIF.] [Illustration: TWO ROWS OF AIRPLANES LINED UP AT A TEXAS FLYING FIELD.] America succeeded, once the requirements were known, in producing the various accessories of aerial warfare. It was necessary first to learn from foreign sources what these accessories were and how they should be built; but as a rule it was possible to adapt American production resources to the problem, and the difficulties experienced were rather those of determining requirements and the exact adaptation of the various articles to specific airplanes. The achievements of America in aircraft production during the war period may be summarized as follows: In our 19 months of warfare we outdid any one of the belligerent nations in Europe in the production of airplanes in its first 19 months of intensive production. In our second year of war we nearly equaled the record of England in her third. At the end of the effort, after our designers had saturated themselves in the science and were abreast of the developments of Europe, they produced several typical American airplanes which gave promise of being superior to any that Europe was turning out. We created one of the three or four best airplane engines, if not the best of all, that the world had seen, and produced it in great quantities. We took a standard but complicated aero-engine from Europe and not only duplicated it in quantity here but turned out a finer product than the original French makers had been able to obtain with their careful and more leisurely methods. In the steel cylinders of all the aero-engines we built was a capacity for producing some seven or eight million horsepower, an energy equivalent to one-fifth of the commercially practicable water power of the United States. The Liberty engines built could alone do the work of the entire flood of Niagara and have a million horsepower to spare. In three years of warfare the allies had been able to develop only a single machine gun that could be successfully synchronized to fire through a revolving airplane propeller. In 12 months of actual effort America produced two others as good, both susceptible of factory quantity production.