And when the question of producing a standardised engine was considered every facility was given and all our experience placed at the disposal of the American Government, with the result that the Liberty engine was evolved." Meanwhile the constant adaptation to new conditions required in the force stimulated the wits of everybody concerned.

Take aerial photography.

The first successful photograph was taken in November, 1914, of the village of Neuve Chapelle.

The photographic section then consisted of two officers and three men, with two cameras and a portable box of chemicals.

At the present day it contains 250 officers and 3,000 men--with a large training school; and its prints have been issued by the million.
Meanwhile the development of our aircraft fire had driven the aerial photographer from a height of 3,000 feet up to a height of 22,000, where, but for invention, he might have perished with cold, or found it impossible to breathe.