631. The rate of march is regulated by the commander of the leading company of each regiment, or, if the battalions be separated by greater than normal distances, by the commander of the leading company of each battalion. He should maintain a uniform rate, uninfluenced by the movements of troops or mounted men in front of him.
The position of companies in the battalion and of battalions in the regiment is ordinarily changed daily so that each in turn leads.
632. The marching efficiency of an organization is judged by the amount of straggling and elongation and the condition of the men at the end of the march.
An officer of each company marches in its rear to prevent undue elongation and straggling.
When necessary for a man to fall out on account of sickness, he should be given a permit to do so. This is presented to the surgeon, who will admit him to the ambulance, have him wait for the trains, or follow and rejoin his company at the first halt.
633. Special attention should be paid to the rate of march. It is greater for trained than for untrained troops; for small commands than for large ones; for lightly burdened than for heavily burdened troops. It is greater during cool than during hot weather. With trained troops, in commands of a regiment or less, marching over average roads, the rate should be from 2-3/4 to 3 miles per hour. With larger commands carrying full equipment, the rate will be from 2 to 2-1/2 miles per hour.
634. The marching capacity of trained infantry in small commands is from 20 to 25 miles per day. This distance will decrease as the size of the command increases. For a complete division the distance can seldom exceed 12-1/2 miles per day unless the division camps in column.
635. In large commands the marching capacity of troops is greatly reduced by faulty march orders and poor march discipline.
The march order should contain such instructions as will enable the troops to take their proper places in column promptly. Delay or confusion in doing so should be investigated. On the other hand, organization commanders should be required to time their movements so that the troops will not be formed sooner than necessary.
The halts and starts of the units of a column should be regulated by the watch and be simultaneous.