he best means of covering the head and
flanks of the column will be by a line of skirmishers extended at
intervals of from 5 to 50 yards, as, for instance, when passing
through high corn, underbrush, etc.

It must always be remembered that the principal duty of the advance
guard is to secure the uninterrupted march of the main body. If
the point is fired upon, it should at once deploy and endeavor to
advance fighting. The flankers should assist in this and endeavor
to locate the enemy's flank should there be such resistance that
advance was impossible. Each succeeding body should march promptly
forward, and in turn be placed in action, with the idea of clearing
the way for the advance of the main body. Should this be impossible,
the commander of the entire body must determine what measures he
will take.

SECTION 5. REAR GUARDS.

A rear guard is a detachment detailed to protect the main body
from attack in rear. In a retreat it checks pursuit and enables
the main body to increase the distance between it and the enemy
and to re-form if disorganized. The general formation is that
of an advance guard reversed.

Its commander should take advantage of every favorable opportunity
to delay the pursuers by obstructing the road or by taking up
specially favorable positions from which to force the enemy to
deploy. In this latter case care must be taken not to become so
closely engaged as to render withdrawal unnecessarily difficult.
The position taken should be selected with reference to ease of
withdrawal and ability to bring the enemy under fire at long
ranges.

SECTION 6. FLANK GUARDS.

A flank guard is a detachment detailed to cover the flank of a
column marching past, or across the front of, an enemy. It may
be placed in position to protect the passage, or it may be so
marched as to cover the passage. The object of the flank guard
is to hold the enemy in check long enough to enable the main body
to pass, or, like the advance guard, to enable the main body
to deploy. Like all other detachments, it should be no larger
than is necessary, and should not be detailed except when its
protection is required.

When a flank guard consists of a regiment or less, its distance
from the main body should not exceed a mile and a half. Practicable
communication must exist between it and the main body. The flank
guard is marched as a separate command; that is, with advance or
rear guards, or both, as circumstances demand, and w