he raids of October 2,
1915, on the stations of Vosiers and Challeranges, sixty-five machines
were employed. A few days later a fleet of eighty-four French
aeroplanes made a raid on the German lines, starting from an aerodrome
near Nancy. Since then raids by large flocks of aeroplanes have become
common.

One important objective of such attacks was the destruction of the
enemy's communication, and the bombing of railway trains bringing up
supplies or reenforcements, became a most important feature. Often
this involved considerable daring on the part of the pilot and his
companion, as to insure a successful dropping of bombs the aeroplanes
had to descend to comparatively low levels. The British Royal Flying
Corps on several occasions dropped bombs from a height hardly more
than 500 feet, and in the operations at the end of September, 1915,
within five days, nearly six tons of explosives were dropped on moving
trains with considerable damage.

The most striking feature, perhaps in the work of the aeroplanes, was
the increased height of flight which developing conditions made
necessary. At the beginning of the war it was assumed that overhead
reconnaissance could be carried on in safety at a height of from 4,000
to 6,000 feet above the surface of the earth. At such altitude it was
assumed that the aeroplane was safe from terrestrial artillery on
account of offering so small a target, as well as on account of its
speed and the difficulty of determining its range, but this condition
of affairs did not long remain. Both armies, and particularly the
Germans, acquired experience in the use of their antiaircraft guns,
and improved weapons were placed at their disposal, so that it was not
long before the gunners could cause their shrapnel to burst with
deadly effect some three miles in vertical height above the ground,
and up to 10,000 feet their shooting compelled the admiration of the
aviators of the Allies.

Such efficient gunnery practice, of course, contributed to the loss of
life among the aviators and the destruction of machines,
notwithstanding the constantly increased height of flying. In some
cases aeroplanes managed to reach the ground safely with as many as
300 bullet holes, but in other cases a single bullet sufficed to kill
the aviator or to hit a vital part, and this was a compelling reason
for armoring the aeroplanes and protecting their engines and controls.

All of this naturally produced a higher standard