CHAPTER XI.
Marches (Continued)
Respecting the length of a march and the time it requires, it is natural for us to depend on the general results of experience.
For our modern armies it has long been settled that a march of three miles should be the usual day’s work which, on long distances, may be set down as an average distance of two miles per day, allowing for the necessary rest days, to make such repairs of all kinds as may be required.
Such a march in a level country, and on tolerable roads will occupy a division of 8,000 men from eight to ten hours; in a hilly country from ten to twelve hours. If several divisions are united in one column, the march will occupy a couple of hours longer, without taking into account the intervals which must elapse between the departure of the first and succeeding divisions.
We see, therefore, that the day is pretty well occupied with such a march; that the fatigue endured by a soldier loaded with his pack for ten or twelve hours is not to be judged of by that of an ordinary journey of three miles on foot which a person, on tolerable roads, might easily get over in five hours.
The longest marches to be found in exceptional instances are of five, or at most six miles a day; for a continuance four.
A march of five miles requires a halt for several hours; and a division of 8,000 men will not do it, even on a good road, in less than sixteen hours. If the march is one of six miles, and that there are several divisions in the column, we may reckon upon at least twenty hours.
We here mean the march of a number of whole divisions at once, from one camp to another, for that is the usual form of marches made on a theatre of war. When several divisions are to march in one column, the first division to move is assembled and marched off earlier than the rest, and therefore arrives at its camping ground so much the sooner. At the same time this difference can still never amount to the whole time, which corresponds to the depth of a division on the line of march, and which is so well expressed in French, as the time it requires for its découlement (running down). The soldier is, therefore, saved very little fatigue in this way, and every march is very much lengthened in duration in proportion as the number of troops to be moved increases. To assemble and march off the different brigades of a division, in like manner at different times, is seldom practicable, and for that reason we have taken the division itself as the unit.
In long distances, when troops march from one cantonment into another, and go over the road in small bodies, and without points of assembly, the distance they go over daily may certainly be increased, and in point of fact it is so, from the necessary detours in getting to quarters.
But those marches, on which troops have to assemble daily in divisions, or perhaps in corps, and have an additional move to get into quarters, take up the most time, and are only advisable in rich countries, and where the masses of troops are not too large, as in such cases the greater facilility of subsistence and the advantage of the shelter which the troops obtain compensate sufficiently for the fatigue of a longer march. The Prussian army undoubtedly pursued a wrong system in their retreat in 1806 in taking up quarters for the troops every night on account of subsistence. They could have procured subsistence in bivouacs, and the army would not have been obliged to spend fourteen days in getting over fifty miles of ground, which, after all, they only accomplished by extreme efforts.