r the first 24 hours after
relief.
(b) General information of the enemy's lines, dispositions, and
intentions, based chiefly on aerial photographs.

C. ORGANIZATION OF DEFENSE:

1. Allocation of front. (The front of an American battalion will
average about 1,000 yards.)
Diagrams: A. The Regiment. B. The Battalion. C. The Company. D.
The Platoon.
2. Distribution of effectives. Determined chiefly by the terrain
and by 3.
3. Employment of the several arms:
(a) Machine guns. Crew of 8 men per gun. (Furnished by
detachments of a machine gun company.) Located by the
infantry commander, in concealed emplacements behind the
first line, to deliver successive barrages from flanking
positions. Effective range: up to 700 yards.
(b) Automatic rifles. Crew of 3 men per rifle. Usually posted to
enfilade the entanglements of the first line. They
concentrate the fire effect of from 7 to 10 riflemen.
Effective range: up to 300 yards.
(c) Rifle Grenadiers. Located near enough to first line to hold
the enemy trenches under fire and deliver effective barrages
near the mouths of our own communicating trenches. Should be
located near observation posts so that their fire can be
promptly corrected.
(d) Trench mortars. Located similarly to (c). Manned by
riflemen.
(e) Bombers. One supply man to each 2 grenadiers. Used for
protection of auto-rifles, in counter attacks, for
protection of communicating trenches and fighting in close
quarters.
(f) Riflemen. Posted to deliver frontal fire. Grouped according
to the plan of counter attacks.
(g) As many men as possible should be instructed in the use of
the enemy's weapons.

D. LIAISON:

(a) By telephone. Quickest and most accurate. Maintained
between each platoon and its company headquarters, and
between adjoining companies. Especially subject to
destruction in bombardment. Wireless and ground telegraphy
are used only between brigade and division headquarters.
(b) By runners ("liaison agents"). Five detailed from each
company to battalion headquarters; one sent to each
adjoining company headquarters; one from each platoon to
company headq