Artillery increases the destructive principle of fire; it is the most redoubtable of arms, and its want, therefore, diminishes very considerably the intensive force of an army. On the other hand, it is the least moveable, consequently, makes an army more unwieldy; further, it always requires a force for its support, because it is incapable of close combat; if it is too numerous, so that the troops appointed for its protection are not able to resist the attacks of the enemy at every point, it is often lost, and from that follows a fresh disadvantage, because of the three arms it is the only one which in its principal parts, that is guns and carriages, the enemy can soon use against us.
Cavalry increases the principle of mobility in an army. If too few in number the brisk flame of the elements of war is thereby weakened, because everything must be done slower (on foot), everything must be organised with more care; the rich harvest of victory, instead of being cut with a scythe, can only be reaped with a sickle.
An excess of cavalry can certainly never be looked upon as a direct diminution of the combatant force, as an organic disproportion, but it may certainly be so indirectly, on account of the difficulty of feeding that arm, and also if we reflect that instead of a surplus of 10,000 horsemen not required we might have 50,000 infantry.
These peculiarities arising from the preponderance of one arm are the more important to the art of war in its limited sense, as that art teaches the use of whatever forces are forthcoming; and when forces are placed under the command of a general, the proportion of the three arms is also commonly already settled without his having had much voice in the matter.
If we would form an idea of the character of warfare modified by the preponderance of one or other of the three arms it is to be done in the following manner:—