arger British machines a record of ninety-five pounds has been
attained. The most common form of bomb used in the heavier-than-air
machines was pear-shaped, with a whirling tail to keep the missile
upright as it falls. Steel balls within, a little larger than
ordinary shrapnel, are held in place by a device which releases them
during the fall. On striking the ground they fall on the explosive
charge within and the shell bursts, scattering the two or three
hundred steel bullets which it carries over a wide radius. Bombs of
this character weigh in the neighbourhood of six pounds and an
ordinary airplane can carry a very considerable number. Their
exploding device is very delicate so that it will operate upon
impact with water, very soft earth, or even the covering of an
airship. Other bombs commonly used in airplanes were shaped like
darts, winged like an arrow so that they would fall perpendicularly
and explode by a pusher at the point which was driven into the body
of the bomb upon its impact with any hard substance.

It seems curious to read of the devices sometimes quite complicated
and at all times the result of the greatest care and thought, used
for dropping these bombs. In the trenches men pitched explosive
missiles about with little more care than if they had been so many
baseballs, but only seldom was a bomb from aloft actually delivered
by hand. In the case of the heavier bombs used by the dirigibles
this is understandable. They could not be handled by a single man
without the aid of mechanical devices. Some are dropped from a
cradle which is tilted into a vertical position after the shell has
been inserted. Others are fired from a tube not unlike the torpedo
tube of a submarine, but which imparts only slight initial velocity
to the missile. Its chief force is derived from gravity, and to be
assured of its explosion the aviator must discharge it from a height
proportionate to its size.

In the airplane the aviator's methods are more simple. Sometimes the
bombs are carried in a rack beneath the body of the machine, and
released by means of a lever at the side. A more primitive method
often in use is merely to attach the bomb to a string and lower it
to a point at which the aviator is certain that in falling it will
not touch any part of the craft, and then cut the string. Half a
dozen devices by which the aviator can hold the bomb at arm's length
and drop it with the certainty of a perpendicular fall are in us