It is true that even now no army can do entirely without some subsistence wagons, but the number is immensely diminished, and little more is required than sufficient to carry the surplus of one day on till the next. Peculiar circumstances, as in Russia in 1812, may even again compel an army to carry an enormous train, and also field-ovens; but in the first place these are exceptional cases; for how seldom will it happen that 300,000 men make a hostile advance of 130 miles upon almost a single road, and that through countries such as Poland and Russia, and shortly before the season of harvest; and in the next place, any means of supply attached to an army in such cases, may be looked upon as only an assistance in case of need, the contributions of the country being always regarded as the groundwork of the whole system of supply. Since the first campaigns of the French revolutionary war, the requisition system has formed constantly the mainstay of their armies, the armies opposed to them were also obliged to adopt the same system, and it is not at all likely that it will ever be abandoned. There is no other which can be substituted for it with the same results, both as regards its simplicity and freedom from restraint, and also as respects energy in the prosecution of the war. As an army is seldom distressed for provisions during the first three or four weeks of a campaign whatever direction it takes, and afterwards can be assisted by magazines, we may very well say that by this method war has acquired the most perfect freedom of action. Certainly difficulties may be greater in one direction than in another, and that may carry weight in preliminary deliberation; but we can never encounter an absolute impossibility, and the attention which is due to the subject of subsistence can never decide a question imperatively. To this there is only one exception, which is a retreat through an enemy’s country. In such a case many of the inconveniences connected with subsistence meet together. The operation is one of a continuous nature, generally carried on without a halt worth speaking of; there is, therefore, no time to procure provisions; the circumstances under which the operation commences are generally unfavourable, it is therefore necessary to keep the troops in masses, and a dispersion in cantonments, or even any considerable extension in the width of the column cannot be allowed; the hostile feeling of the country precludes the chance of any collection of contributions by mere orders issued without the support of a force capable of executing the order; and, lastly, the moment is most auspicious for the inhabitants to give vent to their feelings by acts of hostility. On account of all this, an army so situated is generally obliged to confine itself strictly to its previously prepared lines of communication and retreat.