Whatever be the order of battle, a strong reserve of troops is necessary, in order that any part of the army may be succoured by it when weakened by losses, or when in danger of being overpowered by numbers. At the battle of Albuera, the timely bringing up of the reserve, when the first line was destroyed, was the means of the victory being gained ; and at the battle near Bayonne, December, 1813, two British regiments having been improperly withdrawn from an import ant position, that position was in danger of being lost, when General Hill brought up the reserve and maintained the action. Strong re serves are particularly necessary when armies engage on a plain, as then the whole line may be forced into action, and in the event of being defeated, its ruin would be inevitable without the support of a numerous body of troops.
When cavalry commence an action, its charge should be preceded by a fire of horse-artillery placed on one of its wings. The fire of that artillery should at first be directed against some part of the enemy's line which is at a distance from the point to be attacked; sod if the latter point should be weakened by troops being withdrawn from it to strengthen that point against which the fire is directed, the artillery and cavalry immediately move rapidly forward : the former, having discharged some rounds of grape-shot, retires, and the cavalry is left to execute its charge. Should the artillery become mixed with the com batants, it would be in danger of being taken by the enemy, whereas, being kept in reserve, it may after the charge either join in the pursuit or protect the retreat.
Infantry generally commences an attack by a fire of light troops ; and these are accompanied by a part of the artillery, which joins in the firing, the rest remaining in reserve. If the skirmishers retire in order to allow the first lino of the army to engage the enemy, the reserve artillery is brought up with that line, and it disposes itself by the side of that which had previously been in action, or it goes to one of the wings. Should the enemy's line become disordered, the horse-artillery gallops up to within range of grape-shot and completes the victory.
The stations of artillery in position should, if possible, be such that the fire of the guns may converge towards some battery of the enemy, in which case the fire of such battery against those guns is necessarily divergent. In general, when an army acts on the offensive, the lines of fire from batteries in position should form nearly right angles with the front of the position, in order that the attacking columns may have room to form in the intervals between those lines of fire; but if the enemy be the assailant, the lines of fire may form acute angles with the position, in order that he may be thereby annoyed when nearly in contact with the troops ; the fire of the artillery being directed against the points where the enemy's troops are in masses, as against the heads and flanks of the columns of attack. The guns should not, however,
be placed in position till they are wanted, in order that they may be as little as possible exposed to the fire of the enemy ; and if any battery is subject to a heavy cannonade, another should be immediately placed in a situation where its fire may cross that of the first battery on the ground occupied by the enemy's guns. When placed on elevated ground, the guns in a battery should be able to defend all the slope of the height up to them ; and when that is not possible without bringing them so near the brow as to be exposed to the view of the enemy, other guns should bo placed where their fire may flank the ascending ground.
Artillery consisting of 9-pounder guns is found moat convenient for the batteries which are placed with the troops : such guns are capable of serving to defend the position, and they may be employed to destroy walls, displace abatis, or ruin field intrenehments. Howitzers are also used in the field for the purpose of throwing shells into redoubts or villages, or among troops protected by hedges, hollow ways, &e., where the shot from gun-batteries could not take effect. To these must now be added rifled guns. [Onnxascis, Ittrun.] Horse artillery should be kept with the reserve, and be ready to advance wherever it may be required, either to support a part of the line which is like's to be forced, or to gain the flanks or rear of the enemy ; and when it is required to get possession of a position before the enemy can arrive at it, the horse-artillery, on account of the rapidity of its motion, may bo employed for the purpoee.
The batteries by which an army is protected in its position consti tute a sort of bastions, being usually placed a little in advance of the infantry of the line. If the army receives the attack of the enemy, the artillery cotnmenecs the action by a cannonade while the enemy is at a distance ; and if the army acts on the offensive, the artillery sup ports the columns of attack. It is usual, when guns are fired in position, to direct them so that the shot may strike the ground in front of the enemy's line, and afterwards, by rebounding, make a series of grazes among his troops. When the ground is hard and even, these ricochets are very destructive ; but if soft, or much broken by inequalities, the shot plunges in the ground and does comparatively but little execution. It is doubtful if ricochet fire is practicable or likely to be efficacious with rifled ordnance.