233. When the company is deployed, the men execute the firings at the command of their platoon leaders; the latter give such 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. 234. 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. 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_. 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. 235. 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. 236. Firing with blank cartridges at an _outlined_ or _represented_ enemy at distances less than 100 yards is prohibited. 237. 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. _Ranges._ 238. 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. 239. 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. 240. 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 estimators in the company, are designated as _range estimators_ and are specially trained in estimating distances. Whenever necessary and practicable, the captain assembles the range estimators, points out the target to them, and adopts the mean of their estimates. The range estimators then take their customary posts. (_C.I.D.R., No. 17._) _Classes of Firing._ 241. _Volley firing_ has limited application. In defense it may be used in the early stages of the action if the enemy presents a large, compact target. It may be used by troops executing _fire of position_. When the ground near the target is such that the strike of bullets can be seen from the firing line, _ranging volleys_ may be used to correct the sight setting. In combat, volley firing is executed habitually by platoon.