To keep contact with the enemy--to be acquainted with the terrain;
to protect flanks and rear and guard against surprise.
Reconnaissance begins on entering theater of operations and lasts
through campaign.
Effected by patrols and air craft.

Indications of enemy:
Tracks on road.
Abandoned camps and clothing.
Infantry, thick, low cloud of dust.
Cavalry, high, thin cloud of dust.
Artillery and wagons, broken cloud.

Determination of Enemy Forces:
Timing past a given point.
Cavalry (walk), 110 per minute.
Cavalry (trot), 200 per minute.
Infantry, 175 per minute.
Artillery and wagons, 5 per minute.

Security:
Those measures taken to protect a command from enemy observation,
annoyance and surprise.
Obtained by covering the front with detachments.
March.--Advance, flank and rear guards.
Camp.--Outposts.
March and camp detachments.--To give warning and resist attack until
such time as detachment in rear can deploy.

Advance Guard: