r the development of any device for causing destruction.
Conventions, usages, and prejudices were laid aside and every
possibility of inflicting damage on the enemy was examined on its
merits. Sentiment or any regard for personal danger involved was
thrown to the winds. Science was mobilized in all lines in the
struggle to keep one step ahead of the enemy.

Almost immediately aviation challenged the attention of the
responsible leaders. The handful of French planes which in those early
fateful days of August penetrated up into Belgium brought back the
information of the German mobilization there, and this led to the
rearrangement of French forces in preparation for the battle of the
Marne. As a result aviation at once leaped into high repute for
scouting purposes and the foundations were laid for its great
development.

But as aviation had proved itself in the warfare of movement leading
down to the Marne and sweeping back later to the Aisne, so it proved
itself in the French warfare which was so unexpectedly to follow. When
the two opposing lines were so close together that they locked almost
in a death grip, each side kept such strict watch that ground
observation was greatly hampered. Apparently there was only one way to
find out what was going on behind the enemy's lines. That was by
looking from above. The first aviator, therefore, who sailed into the
air and spied the enemy introduced one of the most important
developments in the strategy of modern warfare.

Thereupon began one of those silent battles of the rear, of which we
see and hear so little, but which indeed decides sometimes far in
advance of the actual test of battle just which side is going to win.
Scientists, inventors, manufacturers, and practical fliers began
coming together in increasing numbers to exact from this latest method
of warfare its last degree of usefulness. In the studies and factories
on both sides of the lines men dedicated themselves to the solution of
the problem of flight.

Stage by stage the difficulties were overcome. First it was the
Germans who with their terrible Fokker planes harnessed the
machine-gun to the airplane and made of it a weapon of offense. Then
it was the Allies who added the radio and made of it an efficient
method of observation and spotting of artillery fire. Increased
engine-power began to be developed, and bombs were carried in
ever-increasing numbers and size.

The moment an enemy plane fell on either