ared for in a similar manner.

=1170. Illumination of the Foreground.= Battlefield illumination is a
necessity where night attacks may be expected, and also as a
protection to the line of obstacles. Portable searchlights have become
an accepted part of every army. In addition to these, trenches must be
supplied with reflector lights, star bombs, rockets and flares,
arranged so that they can be put into action instantaneously when the
enemy approaches.

The foreground should be entirely illuminated, leaving the defenders
in the shadow. If the light is too close to the defenders parapet,
they are illuminated and become a good target. Some flares will burn
for 20 minutes and may be thrown to the front as grenades, fired as
rockets, shot from small mortars, or placed well to the front to be
set off by trip wires close to the ground. The best light devised is
one that can be fired well to the front from a small mortar and then
hung suspended from an open parachute above the enemy. Bonfires can be
laid ready for lighting when no other means is at hand. Whatever form
of illumination is adopted, it should withstand bad weather conditions
and prolonged bombardment.

=1171. Telephones.= When armies have been forced to trench warfare and
time has permitted an elaborate system of trenches to be constructed,
telephone communication is established as soon as possible. The
central station, with the switch-board is located in a shelter in rear
of the cover trenches and lines are run to all trenches, lookout
stations and listening points.

=1172. Siege works.= Comprise devices used by besiegers and besieged
in attack and defense of strong fortifications and especially those
devices enable troops to advance under continuous cover.

CHAPTER XI

OBSTACLES

=1173. Object.= The main objects in placing obstacles in front of the
trenches are, to protect them from surprise, and to stop the enemy's
advance or to delay him while under the defender's fire.

=1174. Necessity for obstacles.= It is evident that the present
tendency is to reduce the number of men assigned to constant occupancy
of the first line trenches. This is due to the effectiveness of rifle
fire at close range, the destructive effect of shell and shrapnel, the
infrequency of daylight attack on intrenched positions, and the severe
strain on the men. The aim seems to be the placing here and there of a
lookout or trench guards, who, when necessity demands can call