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.

We developed new airplane cameras. We carried to new stages the science of clothing aviators. We developed in quantity the wireless airplane telephone that stilled in the ears of the pilot the bedlam of wind and machine guns and engine exhaust and placed him within easy speaking radius of his ground station and his commander in the air.

We built balloons at a rate to supply more than our own needs.

When the shortage of linen threatened the entire airplane output of the nations opposing Germany, we developed cotton wing fabric that not only substituted for linen, but proved to be better; and in producing a liquid filler to make this fabric wind-tight we established on a large scale an entirely new chemical industry in the United States.

Such were the high points in the history of America's aircraft production for war. The details of the developments which led to these results are set forth on the following pages.

VIEW OF AIRPLANE IN FLIGHT TAKEN FROM ANOTHER MACHINE.