commands as are necessary to carry out
the captain's directions, and, from time to time, add such further
commands as are necessary to continue, correct, and control, the fire
ordered. (233)

=271. Use of signals during firing.= The voice is generally inadequate
for giving commands during fire and must be replaced by signals of
such character that proper fire direction and control is assured. (See
par. 92 for signals; pars. 285-286 for fire direction and pars.
287-290 for fire control.) To attract attention, signals must usually
be preceded by the whistle signal (short blast). A fraction of the
firing line about to rush should, if practicable, avoid using the long
blast signal as an aid to cease firing. (See par. 91.) Officers and
men behind the firing line can not ordinarily move freely along the
line, but must depend on mutual watchfulness and the proper use of the
prescribed signals. All should post themselves so as to see their
immediate superiors and subordinates. (234)

=272. Duties of musicians.= The musicians assist the captain by
observing the enemy, the target, and the fire-effect, by transmitting
commands or signals, and by watching for signals. (For posts of
musicians see par. 207.) (235)

=273. Blank Cartridges.= Firing with blank cartridges at an outlined
or represented enemy (par. 7) at distances less than 100 yards is
prohibited. (236)

=274. Effect of fire and influence of ground.= The effect of fire and
the influence of the ground in relation thereto, and the individual
and collective instruction in marksmanship, are treated in the
Small-Arms Firing Manual. (237)

Ranges

=275. Classification.= For convenience of reference, ranges are
classified as follows:

0 to 600 yards, close range.
600 to 1,200 yards, effective range.
1,200 to 2,000 yards, long range.
2,000 yards and over, distant range. (238)

=276. Determination of distance to target.= The distance to the target
must be determined as accurately as possible and the sights set
accordingly. Aside from training and morale, this is the most
important single factor in securing effective fire at the longer
ranges. (239)

=277. Method of determining the range; estimators.=

Except in a deliberately prepared defensive position, the most
accurate and only practicable method of determining the range will
generally be to take the mean of several estimates.

Five or six officers or men, selected from the most accurate
esti