The powder magazines to serve the batteries ought to be at a convenient distance from the same, as also from each other; the large one, at least 55 feet in the rear of the battery, and the small ones about 25. Sometimes the large magazines are made either to the right or left of the battery, in order to deceive the enemy; they are generally built 5 feet under ground; the sides and roof must be well secured with boards, and covered with earth, clay, or something of a similar substance, to prevent the powder from being fired: they are guarded by centinels. The balls are piled in readiness beside the merlins between the embrasures.
The officers of the artillery ought always to construct their own batteries and platforms, and not the engineers, as is practised in the English service; for certainly none can be so good judges of those things as the artillery officers, whose daily practice it is; consequently they are the properest people to direct the situation and to superintend the making of batteries on all occasions.
Mortar-Battery. This kind of battery differs from a gun-battery, only in having no embrasures. It consists of a parapet of 18 or 20 feet thick, 7¹⁄₂ high in front, and 6 in the rear; of a berm 2¹⁄₂ or 3 feet broad, according to the quality of the earth; of a ditch 24 feet broad at the top, and 20 at the bottom. The beds[37] must be 9 feet long, 6 broad, 8 from each other, and 5 feet from the parapet: they are not to be sloping like the gun platforms, but exactly horizontal. The insides of such batteries are sometimes sunk 2 or 3 feet into the ground, by which they are much sooner made than those of cannon. The powder magazines and piles of shells are placed as is mentioned in the article Gun-Battery.
Ricochet-Battery, so called by its inventor M. Vauban, and first used at the siege of Aeth in 1697. It is a method of firing with a very small quantity of powder, and a little elevation of the gun, so as just to fire over the parapet, and then the shot will roll along the opposite rampart, dismounting the cannon, and driving or destroying the troops. In a siege they are generally placed at about 300 feet before the first parallel, perpendicular to the faces produced, which they are to enfilade. Ricochet practice is not confined to cannon alone; small mortars and howitzers may effectually be used for the same purpose. They are of singular use in action to enfilade an enemy’s ranks; for when the men perceive the shells rolling and bouncing about with their fuzes burning, expecting them to burst every moment, the bravest among them will hardly have courage to await their approach and face the havoc of their explosion.