The rough line or lines of columns thus formed enable troops to take advantage of the terrain in advancing and shorten the time occupied in forming the firing line.
[426.] In deploying the division each brigade is assigned a definite task or objective. On receipt of his orders, the brigade commander conducts his brigade in column or in line of regiments until it is advisable that it be broken into smaller columns. He then issues his order, assigning to each regiment its task, if practicable. In a similar manner the regimental commanders lead their regiments forward in column, or in line of columns, until the time arrives for issuing the regimental order. It is seldom advisable to break up the battalion before issuing orders for its deployment.
[427.] Each subordinate commander, after receiving his order for the action, should precede his command as far as possible, in order to reconnoiter the ground personally, and should prepare to issue his orders promptly.
[428.] Each commander of a column directs the necessary reconnaissance to front and flank; by this means and by a judicious choice of ground he guards against surprise.
[429.] The premature formation of the firing line causes unnecessary fatigue and loss of time, and may result in a faulty direction being taken. Troops once deployed make even minor changes of direction with difficulty, and this difficulty increases with the length of the firing line.
[430.] In the larger units, when the original deployment is found to be in the wrong direction, it will usually be necessary to deploy the reserve on the correct front and withdraw and assemble the first line.
[431.] To gain decisive results, it will generally be necessary to use all the troops at some stage of the combat. But in the beginning, while the situation is uncertain, care should be taken not to engage too large a proportion of the command. On the other hand, there is no greater error than to employ too few and to sacrifice them by driblets.
[432.] When it is intended to fight to a decision, fire superiority is essential. To gain this, two things are necessary: A heavy fire and a fire well directed and controlled. Both of these are best obtained when the firing line is as dense as practicable, while leaving the men room for the free use of their rifles.
If the men are too widely separated, direction and control are very difficult, often impossible, and the intensity of fire is slight in proportion to the front occupied.
[433.] In an attack or stubborn defense the firing line should have a density of one man per yard of front occupied.