correct any minor fault.

In our army, and indeed in all others, applicants for appointment to
the aviation corps were subjected to scientific tests of their
nerves, and their mental and physical alertness. How they would
react to the sudden explosion of a shell near their ears, how long
it took the candidate to respond to a sudden call for action, how
swiftly he reacted to a sensation of touch were all tested and
measured by delicate electric apparatus. A standard was fixed,
failing to attain which, the applicant was rejected. The practical
effect might be to determine how long after suddenly discovering a
masked machine gun a given candidate would take before taking the
action necessary to avoid its fire. Or how quickly would he pull the
lever necessary to guard against a sudden gust of wind. To the
layman it would appear that problems of this sort could only be
solved in the presence of the actual attack, but science, which
enables artillerists to destroy a little village beyond the hills
which they never see, was able to devise instruments to answer these
questions in the quiet of the laboratory.

One of the best known flying schools of the French army was at Pau,
where on broad level plains were, in 1917, four separate camps for
aviators, each with its group of hangars for the machines, its
repair shops, and with a tall wireless tower upstanding in the
midst for the daily war news from Paris. On these plains the Wright
Brothers had made some of their earliest French flights. A little
red barn which they had made their workshop was still standing there
when war suddenly turned the spot into a flying school often with as
many as five thousand pupils in attendance. "To-day that little red
barn," writes Carroll Dana Winslow, one of the Americans who went to
fly for France, "stands as a monument to American stupidity, for
when we allowed the Wrights to go abroad to perfect their ideas
instead of aiding them to carry on their work at home we lost a
golden opportunity. Now the United States which gave to the world
the first practical airplane is the least advanced in this
all-important science."

Arrived at the school the tyro studies the fundamentals of flying in
the classroom and on the field for two months before he is allowed
to go up--to receive as they express it, his _bapteme de l'air_. He
picks motors to pieces, and puts them together, he learns the
principles of airplane construction, and can discourse on suc