nning used the art of camouflage. This was resorted to
particularly against scouting airplanes. At first the branches of trees
and similar natural cover were used to deceive the airmen. Later the
guns themselves were painted with protective colorations, and screens of
burlap were used instead of branches. The camoufleur, as the camouflage
artist was called, speedily extended his activities to screens over
highways, preventing airmen from seeing troops in motion, to the
protective coloration of lookout posts, and of other necessary factors
along the fighting front. Camouflage also found great usefulness in the
protective coloration of battleships and merchant vessels. Scientific
study went hand in hand with the art, the object being to confuse the
enemy and to offer targets as small as possible to the enemy gunners.

Crater warfare came as a development of intensified artillery attacks
upon trench systems. It was at Dunajec on the eastern front that for the
first time in modern war the wheels of artillery were placed hub to hub
in intensified hurricane fire upon enemy positions. The result there
under von Mackensen's direction was the rout of the Russians. When later
the same tactics were employed on the western front, the result was to
destroy whole trench systems with the exception of deep dugouts, and to
send the occupants of the trenches into the craters, made by shell
explosions, for protection.

It was observed that, these craters made excellent cover and when linked
by vigorous use of the intrenching tools carried by every soldier, they
made a fair substitute for the trenches. This observation gave root to
an idea which was followed by both armies; this was the deliberate
creation of crater systems by the artillery of the attacking force. Into
these lines of craters the attacking infantry threw itself in wave after
wave as it rushed toward the enemy trenches. The ground is so riddled by
this intensive artillery fire that there is created what is known as
"moon terrain", fields resembling the surface of the moon as seen
through a powerful telescope. Troops on both sides were trained to
utilize these shell holes to the utmost, each little group occupying a
crater, keeping in touch with its nearest group and moving steadily in
unison toward the enemy.

One detail in which this war surpassed all others was in the use of
machine guns and grenades. The Germans were first to make extensive use
of the machine gun as a w