TACTICAL USE OF ARTILLERY.

The subject will be treated under the following heads:-

-How posted with respect to the Ground.

- How posted with respect to our own Troops.

-How posted with respect to the Enemy.

-Posting of Batteries and Pieces as between themselves.

-How used.

-Its Fire.

-Its Supports.

I.-How posted with respect to the Ground.

1. Artillery has a much longer range than musketry. In order to avail ourselves of this advantage, we must so post it as to overlook all the ground to which its utmost range extends. It therefore requires an elevated position.

2. It has been considered an additional advantage of a commanding position for artillery, that it enables our guns to cover our infantry, attacking or attacked, by firing over their heads.

This was done by the French at Waterloo, apparently with great effect. But the advantage is a doubtful one; for firing over our own troops, especially with cast-shot or sh.e.l.l, is very dangerous to them, and is apt to intimidate them. It moreover furnishes to the enemy a double target. The shot which miss our troops will be apt to fall among the guns behind them; and some of those which do not reach the guns, will probably take effect among the troops in front of them.

3. But very high points are unfavorable positions for batteries. Batteries so placed would not command the ground immediately below them; as guns cannot be depressed to fire below a certain angle without soon destroying their carriages. And this would facilitate their capture; for, once arrived on the ground near them, the a.s.sailants could not be injured by their fire. It has been estimated that the slope in front of a battery should not exceed one perpendicular to fifteen base.

4. When guns have to be used as a support to other parts of the line, which is often the case, their capture might lead to serious consequences. They should therefore have the ground clear of all obstacles which may mask their fire, not only in front, but to their right and left.

5. Although the most favorable position for guns is an eminence sloping gradually towards the enemy, an open and level plain is by no means an unfavorable one; for, on such ground, the enemy will be visible at a great distance, and our shot may act by ricochet, which causes more destruction than ordinary point-blank firing.

For ricochet, firm and even ground is requisite; on soft or rough ground it is not attainable.

6. In enfilading the enemy's position, or in raking his advancing columns from head to rear, a grazing fire is the most destructive that can be used. This consists of a long succession of ricochets at low heights. Where the ground is level and firm, we can obtain this fire at a short distance from the enemy; as, on such ground, ricochet shots do not rise much. But where the ground is uneven, to obtain such a fire, a more distant position will be requisite.

7. Muddy ground is unfavorable for artillery. Over such ground, its carriages move slowly, and its fire is less effective. b.a.l.l.s cannot ricochet; and sh.e.l.ls often sink into the mud, and thus are either extinguished or explode with but little effect.

Napoleon depended so much on his artillery at Waterloo that, although every moment was precious, he delayed commencing the battle till his chief of artillery had reported the ground, which had been covered by a soaking rain, to be sufficiently dry for the movements and effectiveness of that arm. The three hours' delay thus caused, would have sufficed him to crush Wellington's army before the arrival of the Prussians.

8. Stony ground is a bad location for a battery; for the enemy's shot will scatter the stones around it with more or less fatal effect.

9. Rough or uneven ground immediately in front of a battery is not objectionable, as it will stop the enemy's shot.

10. A battery, when it is possible to avoid it, should not be posted within musket range of woods, bushes, ravines, hedges, ditches, or other cover from which the enemy's sharpshooters might kill off the gunners, or, by a sudden dash, capture the guns.

11. To prevent the enemy from approaching a battery under cover, it should be so placed as to be able to sweep all villages, hollows, and woods, in front and in flank.

12. In taking up a position, a battery should avail itself of all inequalities of the ground, for the shelter of its pieces and gunners, or of its limbers and caissons, at least.

For the same purpose, a battery posted on an eminence should have its pieces some ten paces behind its crest.

13. Where the ground affords no shelter, and where the position of the guns is not likely to be changed, it may be worth while to cover them by an epaulement or breastwork, some three feet, or more, high.

II.-How posted with respect to our own Troops.

1. In order to be ready to support the flanks of our attacking columns, and to aid in the defence in every part of the field, batteries should be placed at several different points in the line of battle.

2. In a defensive battle especially, as it is uncertain on what point the enemy will ma.s.s his princ.i.p.al attack, the artillery should usually be distributed through the whole line.

3. A line of battle has been compared to the front of a fortification, of which the infantry is the curtain, and the artillery batteries the bastions.

4. The lighter guns should be placed on the salient points of our line, from which they can be more easily withdrawn; the heavier guns, const.i.tuting the stationary batteries, on the more retired points.

5. Pieces should not be placed in prolongation with troops; for this would be giving the enemy a double mark. Artillery posted in front of other troops will draw a fire on them. When a battery must be placed in front of the line, let the infantry in rear of it clear the ground by ploying into double columns.

6. Never place artillery so as to impede the movements of the other two arms. A battery posted in front of the centre would often hamper the movements of the infantry; besides being peculiarly exposed to a converging fire from the enemy's batteries.

7. The safest position for a battery is on that wing which is most secure from a flank attack.

But guns should re-enforce the weaker points, thus making the enemy attack the strongest ones.

Therefore, where a wing is weak, place the largest number of guns there, to support it. If we have one wing entirely uncovered, of four batteries, for instance, we should give three to the uncovered wing.

8. Of the heavy batteries, one, at least, should be placed in the first line, so that we may be able to open an effective fire on the enemy at the earliest possible moment.

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 echarpe, 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.

4. For this reason, we must never post one of our own batteries so that the enemy's guns will take it obliquely, or in flank; unless, indeed, by doing so, we may probably obtain some important and decisive effect before it can be destroyed, or made unserviceable.

5. Batteries should be so placed as to command the whole ground in our front, even almost up to our bayonets, and so as to be able to direct their fire towards every point; at all events, so that a fire can be kept up on the enemy till he is within short musket-range.

It is manifest that the best position for a battery, to enable it to effectually cover the entire ground in our front, would not be in our line of battle, but in advance of one of its flanks, from which it could take the enemy's troops advancing over it, in enfilade.

6. Artillery fire from an unexpected quarter always has a powerful moral effect. Two guns, even, hoisted up to a place where the enemy does not dream of there being any, may have a decisive effect.

IV.-Posting of Batteries and of Pieces as between themselves.

1. The best mode of posting batteries is in the form of a crescent, its horns pointing towards the enemy, or forming the sides of a re-entering angle; for this gives a convergent fire to the enemy's divergent one.