Louis XIV. and Frederick II. fought mostly on their own frontiers, and followed the system of regular depots and supplies.  But the revolutionary armies of France made war without magazines, subsisting, sometimes on the inhabitants, sometimes by requisitions levied on the country passed over, and at others by pillage and marauding.  Napoleon found little difficulty in supporting an army of a hundred or a hundred and twenty thousand men in Italy, Suabia, and on the rich borders of the Rhine and the Danube; but in Spain, Poland, and Russia, the subject of subsistence became one of extreme embarrassment.

All depots of provisions and other supplies for an army are denominated magazines; these are divided into principal, secondary, and provisional.  The first are usually on the base of operations; the second, on the line of operations; and the last in the immediate vicinity of the troops, and contain supplies for a few days only.

The system of magazines is objected to by some, because it fetters the movements of an army, and makes its military operations subordinate to the means of supply.  Moreover, as the movements of an army must be so arranged as to cover these magazines, their establishment at given points reveals to the enemy our plan of campaign.

On the other hand, the system of requisitions, either for immediate supplies or for secondary magazines, gives far greater velocity and impetuosity to an active army; and if it be so regulated as to repress pillage, and be levied with uniformity and moderation, it may be relied on with safety in well-cultivated countries; but in more barren and less populous districts, an army without magazines, especially in case of a prolonged stay or a forced retreat, will be exposed to great suffering and loss, if not to total destruction.

Before commencing a campaign the general should make himself acquainted with all the resources of the country to be passed over—­determine the amount of supplies which it may be necessary to take with him, and the amount that can be obtained by requisitions; these requisitions being levied in a uniform and legal manner, and through the existing local authorities.

In great wars of invasion it is sometimes impracticable, at least for a time, to provide for the immense forces placed on foot, by any regular system of magazines or of ordinary requisitions:  in such cases their subsistence is entirely intrusted to the troops themselves, who levy contributions wherever they pass.  The inevitable consequences of this system are universal pillage and a total relaxation of discipline; the loss of private property and the violation of individual rights, are followed by the massacre of all straggling parties, and the ordinary peaceful and non-combatant inhabitants are converted into bitter and implacable enemies.

In this connection the war in the Spanish peninsula is well worthy of study.  At the beginning of this war Napoleon had to choose between methodical operations, with provisions carried in the train of his army, or purchased of the inhabitants and regularly paid for; and irregular warfare, with forced requisitions—­war being made to support war.  The question was thoroughly discussed.