9. The prompt use, at the proper moment, of the reserve, may decide the battle. The movements of heavy artillery, therefore, are too slow for the reserve, which should have most of the light pieces. Horse artillery is especially suitable for it.
10. Guns near an infantry square should be posted at its angles. If the square is charged by cavalry, the gunners run into the square, after filling their ammunition pouches, which they take in with them, as well as their sponges and other equipments. The limbers and caissons are sent to the rear; or, if there is no time to do this, they may be brought into the square. If this is impossible, they may be formed into a barricade.
At Waterloo, on the French cavalry's retiring from their charges on the enemy's squares, the British gunners rushed out from the squares in which they had taken refuge, and plied their guns on the retiring squadrons.
III.—How posted with respect to the Enemy.
1. If the enemy's batteries are concentrated in one position, by placing our own batteries properly we may obtain a powerful cross-fire on them.
2. It is always advantageous to so dispose our batteries as to take those of the enemy in enfilade, or obliquely (en écharpe, as it is called).
At the battle of Murfreesboro', in December, 1862, a rebel battery, being taken in enfilade by one of our own, was silenced in about five minutes.
3. So, also, if we can obtain an oblique or enfilading fire on his troops, it will be very destructive. A flanking battery, raking the enemy's position, is often enough, of itself, to decide a battle.
Thus, the battle of Chippewa was finally decided by our getting a gun or two in a flanking position, enabling us to enfilade the British line.
So, at the battle of Shiloh, the rebels' triumphant advance on the evening of the first day was effectually checked by the fire of our gun-boats Tyler and Lexington, which had taken an enfilading position opposite their right flank.