As the subsistence and shelter of the troops partly decide the choice of a position in general, so also they contribute to a disposition in separate divisions. The attention which they demand comes into consideration along with the other considerations above mentioned; and we seek to satisfy the one without prejudice to the other. In most cases, by the division of an army into five separate corps, the difficulties of subsistence and quartering will be overcome, and no great alteration will afterwards be required on their account. We have still to cast a glance at the distances at which these separated corps may be allowed to be placed, if we are to retain in view the advantage of mutual support, and, therefore, of concentrating for battle. On this subject we remind our readers of what is said in the chapters on the duration and decision of the combat, according to which no absolute distance, but only the most general, as it were, average rules can be given, because absolute and relative strength of arms and country have a great influence. The distance of the advanced guard is the easiest to fix, as in retreating it falls back on the main body of the army, and, therefore, may be at all events at a distance of a long day’s march without incurring the risk of being obliged to fight an independent battle. But it should not be sent further in advance than the security of the army requires, because the further it has to fall back the more it suffers. Respecting corps on the flanks, as we have already said, the combat of an ordinary division of 8000 to 10,000 men usually lasts for several hours, even for half a day before it is decided; on that account, therefore, there need be no hesitation in placing such a division at a distance of some leagues or one or two miles, and for the same reason, corps of three or four divisions may be detached a day’s march or a distance of three or four miles. From this natural and general disposition of the main body, in four or five divisions at particular distances, a certain method has arisen of dividing an army in a mechanical manner whenever there are no strong special reasons against this ordinary method.