ere used by the Japanese
in their war with Russia. The Japanese mortars were mere logs hollowed
out and strengthened by wrappings of bamboo rope. The projectiles fired
from these were empty provision tins filled with high explosives, scraps
of metal, bits of stone or whatever, in the emergency, could be found to
fill them.

The mortars are pitched at an angle and the projectiles are shot with a
skyrocket effect, to land in the trenches or camp of the enemy. The
Germans developed the idea and the perfected mortars are of steel, and
capable of throwing bombs weighing several hundred pounds.

And then the great moving fort which has been called "the tank!" Those
snorting, fire-spitting dragons which were depicted for us in childhood
can scarcely bring to our mind a greater element of the fanciful, the
horrible, and the powerful than the steel hulks which came into being in
this war under the name of "tanks."

We see them in our mind's eye spitting fire as they crossed No Man's
Land, amid the smoke and dust of bursting shells. Keeping steadily on
their courses they dived into huge craters made by exploding shells;
stretched themselves across trenches, brushed trees and boulders aside,
and kept steadily on their courses. German wire entanglements were as so
many pieces of string before their huge frames. Nothing deterred them.
They moved forward into the face of the enemy, reaching the first line
of German trenches. There the soulless devices sat complacently astride
the trenches, and turning their guns along the ditches swept them in
both directions.

THE TANK DEFIES ALL OBSTACLES.

The tanks which were introduced by the English, move along on revolving
platforms, so to speak. These platforms enable the tank to overcome all
obstacles as the caterpillar tread is curved up in the arc of a huge
circle at the front which gives the vehicle its wonderful tractive
powers. This large curvature acts as a huge wheel with a tremendously
long leverage equal to the radius of the circlet or the spokes of the
imaginary wheel of the same diameter. Only that portion of the assumed
wheel which would come in contact with the ground acts as the lever, and
it is just this portion that is reproduced in the front end of a
caterpillar belt.

Although varying in size and details, all tanks have the common
characteristic of being divided into three main compartments between the
two side caterpillar frames. The first is the observation compa