e places between these last two extremes
that require just an average amount of attention, that is to say,
require groups of medium strength.

The groups that are largest and are used at the important places where
danger is most expected, are called "Pickets." (These consist of from
two squads of eight men each to eight squads.) The least important
groups are called "Cossack Posts." (These consist of four men, usually a
noncommissioned officer and three privates.) The groups of average
importance are called "Sentry Squads." (These consist of eight men, a
corporal and seven privates.)

Having discussed in broad terms the security of troops in camp, we are
prepared to consider their security while either advancing upon or
retreating from the enemy. In either case groups are placed between our
main body and the actual or supposed position of the hostile troops.
When we are advancing upon an enemy our advanced groups constitute what
we term the "advance guard." If we are retreating from the enemy, our
rear groups compose the "rear guard." The main general ideas of an
advance guard are illustrated by the husband who takes his wife and
family to his house after an evening's absence. The house is dark and
without occupants. The wife and children are apprehensive of danger. The
husband goes first, turns on the light, and searches for any indications
of an enemy. He looks, if desirable, in the closets and under the beds.
If there is any one that may harm his family it is his duty to find out
and dispose of him.

In the advance guard we have exactly the same general scheme as with
outposts. Far advanced to the front (and often to the sides or flanks)
we have small groups (called, when considered collectively, the "advance
party") whose business it is to inform us of the presence of the enemy.
Next we have a large group ("support") to assist these small and rather
helpless ones in advance in case of difficulty. And last we have a still
larger group ("reserve") that may be called upon in great emergencies.

We should fully understand that all these groups are out to accomplish
several ends, but their one great and ultimate object should be to push
on ahead of the main body so that it may be secure and its march
uninterrupted. To accomplish this it is desirable to get all possible
information about the enemy; it is also desirable to keep him from
getting any information about your own troops.

The ideas are nearly the same with