armored body and the
two tractor belts extend to full length on either side, being so
arranged that the tank can climb a steep slope. From the meager data
obtainable it would appear that the tanks carry from 4 to 6 machine
guns in armored projections built out from the sides. These are
provided with revolving shields permitting two guns to fire in any
direction at one time.

The principle of the tractor is similar to that of those manufactured
in the United States and used commercially in reclamation work. The
addition of the armored body and guns makes the "military tank."

These "tanks" have proven of great value in village fighting, by
smashing down barricades and driving machine guns from their positions
in cellars and houses. They have also been used with some success in
destroying obstacles.

The power of these new engines may be judged from their ability to
smash down trees six inches in diameter and by means of cables to
uproot trees as large as 15 inches in diameter.

These "tanks" are proof against rifle and machine gun fire, but are
unable to withstand even light artillery.

=1205. Helmets.= Steel helmets made their appearance in the European
war in 1915, as a protection to the soldier's head against rifle,
machine gun and shrapnel fire. So successful were they that they are
being furnished to all troops on the battlefield. Already several
millions have been supplied. Where heretofore head wounds accounted
for over 20 per cent of the casualties in trench warfare, the
percentage has been reduced by the wearing of helmets to about one
half per cent. While the helmet does not afford complete protection
against rifle and shrapnel fire, it has been found that hits result
only in severe concussion, where before fatal wound resulted. These
helmets are painted khaki color.

=1206. Masks.= Steel masks for sentinels and snipers have been adopted
by the Germans. This mask covers the head and face with curved
surfaces which deflect bullets. Small eye holes permit a clear view of
the target and a small section is omitted in the lower right side to
permit bringing the rifle against the cheek in firing.

=1207. Periscopes.= Periscopes have been universally adopted in trench
warfare for observing the enemy while keeping completely under cover.
It is a simple arrangement of two mirrors in a vertical tube. The
upper reflects the image of the object to the lower mirror which in
turn reflects it to the eye of the observ