ans and constructs the field works
that it will occupy.

When performing their duties in this connection officers should bear
in mind that profile and construction are simple matters compared with
location and correct tactical use.

586. Intrenchments enable the commander to hold a position with the
least possible number of men and to prolong his line or increase his
reserve.

They are constructed with a view to giving cover which will diminish
losses, but they must not be so built or placed as to interfere with
the free use of the rifle. Fire effect is the first consideration.

587. The trace of a fire trench or of a system of fire trenches
depends upon the ground and the proposed density of the entire firing
line. The trenches are laid out in company lengths, if possible.

Adjoining trenches should afford each other mutual support. The flanks
and important gaps in the line should be protected by fire trenches
echeloned in rear. (Fig. 6).

588. To locate the trace, lie on the ground at intervals and select
the best field of fire consistent with the requirements of the
situation.

A profile should be selected which will permit the fire to sweep the
foreground, require the minimum of labor and time, and permit the best
concealment. No fixed type can be prescribed. The type must be
selected with due regard to the terrain, the enemy, time, tools,
materials, soil, etc.

589. _Hasty cover._ With the intrenching tool, troops can quickly
throw up a low parapet about 3 feet thick which will furnish
considerable cover against rifle fire, but scarcely any against
shrapnel. Such cover is frequently of value to an attack that is
temporarily unable to continue. In time, and particularly at night, it
may be developed into a deep fire or cover trench.

590. _Fire trenches_ should be placed and constructed so as to give a
good field of fire and to give the troops protection behind a vertical
wall, preferably with some head or overhead cover. They should be
concealed or inconspicuous in order to avoid artillery fire or to
decrease its accuracy. They should have natural or artificial
communication with their supports, but in establishing the trace this
is a secondary consideration.

The simplest form of fire trench is deep and narrow and has a flat,
concealed parapet. (Fig. 1.) In ordinary soil, and on a basis of two
reliefs and tasks of 5 feet, it can be constructed in about two hours
with intrenching tools.

This trench