BATTERY
, in the Military Art, a place raised to plant cannon upon, to play with more advantage upon the enemy. It consists of an epaulment or a breastwork, of about 8 feet high, and 18 or 20 feet thick.
In all batteries, the open spaces through which the | muzzles of the cannon are pointed, are called Embrasures, and the distances between the embrasures, merlons. The guns are placed upon a platform of planks &c, ascending a little from the parapet, to check the recoil, and that the gun may be the easier brought back again to the parapet: they are placed from 12 to 16 feet distant from one another, that the parapet may be strong, and the gunners have room to work.
Mortar Batteries differ from the others, in that the slope of the parapet is inwards, and it is without embrasures, the shells being fired quite over the parapet, commonly at an angle of 45 degrees elevation.
Open Battery, is nothing more than a number of cannon, commonly field-pieces, ranged in a row abreast of one another, perhaps on some small natural elevation of the ground, or an artificial bank a little raised for the purpose.
Covered or Masked Battery, is when the cannon and gunners are covered by a bank or breast-work, commonly made of brush-wood, faggots, and earth, called a fascine battery.
Sunk or Buried Battery, is when its platform is sunk, or let down into the ground, so that trenches must be cut in the earth opposite the muzzles of the guns, to serve as embrasures to fire through. This is mostly used on the first making of approaches in besieging and battering a place.
Cross Batteries, are two batteries playing athwart each other upon the same object, forming an angle there, and battering to more effect, because what one battery shakes, the other beats down.
Battery d'Enfilade, is one that scours or sweeps the whole length of a straight line.
Battery en Echarpe, is one that plays obliquely.
Battery de Reverse, or Murdering Battery, is one that plays upon the enemy's back.
Camerade or Joint Battery, is when several guns play upon one place at the same time.
Battery, in Electricity, is a combination of coated surfaces of glass, commonly jars, so connected together that they may be charged at once, and discharged by a common conductor. Mr. Gralath, a German electrician, first contrived to increase the shock by charging several phials at the same time.—Dr Franklin, having analysed the Leyden phial, and found that it lost at one surface the electric fire received at the other, constructed a battery of eleven large panes of sash window glass, coated on both sides, and so connected that the whole might be charged together, and with the same labour as one single pane; then by bringing all the giving sides into contact with one wire, and all the receiving sides with another, he contrived to unite the force of all the plates, and to discharge them at once.—Dr. Priestley describes a still more complete battery. This consists of 64 jars, each 10 inches long, and 2 1/2 inches in diameter, all coated within an inch and a half of the top, forming in the whole about 32 square feet of coated surface. A piece of very fine wire is twisted about the lower end of the wire of each jar, to touch the inside coating in several places; and it is put through a pretty large piece of cork, within the jar, to prevent any part of it from touching the side, by which a spontaneous discharge might be made. Each wire is turned round so as to make a loop at the upper end; and through these loops passes a pretty thick brass rod with knobs, each rod serving for one row of the jars; and these rods are made to communicate together by a chick chain laid over them, or as many of them as may be wanted. The jars stand in a box, the bottom of which is covered with a tin plate; and a bent wire touching the plate passes through the box, and appears on the outside. To this wire is fastened any conductor designed to communicate with the outside of the battery; and the discharge is made by bringing the brass knob to any of the knobs of the battery. When a very great force is required, the size or number of the jars may be increased, or two or more batteries may be used.—But the largest and most powerful battery of all, is that employed by Dr. Van Marum, to the amazing large electrical machine, lately constructed for Teyler's museum at Haarlem. This grand battery consists of a great number of jars coated as above, to the amount of about 130 square feet; and the effects of it, which are truly astonishing, are related by Dr. Van Marum in his description of this machine, and of the experiments made with it, at Haarlem 1785, &c. See also Franklin's Exper. and Observ. and Priestley's History of Electricity.
