ges lying about, and
many fresh graves, are evidences that the enemy is heavily burdened
with wounded or sick.

=987. Flames or Smoke.= If at night the flames of an enemy's camp
fires disappear and reappear, something is moving between the observer
and the fires. If smoke as well as flame is visible, the fires are
very near. If the fires are very numerous and lighted successively,
and if soon after being lighted they go out it is probable the enemy
is preparing a retreat and trying to deceive us. If the fires burn
brightly and clearly at a late hour, the enemy has probably gone, and
has left a detachment to keep the fires burning. If, at an unusual
time, much smoke is seen ascending from an enemy's camp, it is
probable that he is engaged in cooking preparatory to moving off.

If lines of smoke are seen rising at several points along a railway
line in the enemy's rear, it may be surmised that the railroad is
being destroyed by burning the crossties, and that a retreat is
planned.

=988. Limits of vision.= (a) On a clear day a man with good vision can
see:

At a distance of 9 to 12 miles, church spires and towers;
At a distance of 5 to 7 miles, windmills;
At a distance of 2-1/2 miles, chimneys of light color;
At a distance of 2,000 yards, trunks of large trees;
At a distance of 1,000 yards, single posts;
At 500 yards the panes of glass may be distinguished in a window.

(b) Troops are visible at 2,000 yards, at which distance a mounted man
looks like a mere speck; at 1,200 yards infantry can be distinguished
from cavalry; at 1,000 yards a line of men looks like a broad belt; at
600 yards the files of a squad can be counted, and at 400 yards the
movements of the arms and legs can be plainly seen.

(c) The larger, brighter or better lighted an object is, the nearer it
seems. An object seems nearer when it has a dark background than when
it has a light one, and closer to the observer when the air is clear
than when it is raining, snowing, foggy or the atmosphere is filled
with smoke. An object looks farther off when the observer is facing
the sun than when he has his back to it. A smooth expanse of snow,
grain fields or water makes distances seem shorter than they really
are.

Suggestions for the Reconnaissance of Various Positions and Localities

=989.= Cross roads should be reconnoitered in each direction for a
distance depending on how rapidly the patrol must continue on, how far
from