Ball and Chain. For serious offenses soldiers are sometimes sentenced to wear a 6- or 12-pounder ball attached by a chain to the leg.
Ball-cartridge. A cartridge containing a ball.
Ballinamuck. A town in the county of Longford, Ireland. Here, on September 8, 1798, the Irish rebels and their French auxiliaries were defeated and captured.
Ballistea. In antiquity, songs accompanied by dancing, used on occasions of victory.
Ballistic, or Electro-ballistic Machine. Is a machine designed to determine by electricity the initial velocity of a projectile. The West Point ballistic machine, devised for use at the Military Academy by Col. Benton, of the ordnance department, and since adopted by that department, consists of a bed-plate of metal supporting an arc placed in a perpendicular position, and graduated. Suspended perpendicular to the plane of this arc are two pendulums, having a common axis of motion passing through the centre. Two electro-magnets are attached to the horizontal limb of the arc to hold up the pendulums when they are deflected through angles of 90°. There is also an apparatus which records the point at which the pendulums pass each other, when they fall by the breaking of the currents which excite the magnets, two targets being placed so as to support the wires in a position to be cut by the projectile. The velocity of the electric currents being considered instantaneous, and the loss of the power of the magnets simultaneous with the rupture of the currents, it follows that each pendulum begins to move at the instant that the projectile cuts the wire, and that the interval of time corresponds to the difference of the arcs described by the pendulums up to the time of meeting.
Ballistic Pendulum. A machine consisting of a massive block of wood suspended by a bar. It was devised for experiments on the initial velocities of cannon-shot. The shot being fired into the block, the velocity is calculated from the vibrating effect on the pendulum.
Ballistics. Is that branch of gunnery which treats of the motion of projectiles.
Ballistraria. Cruciform apertures in the walls of a stronghold, through which the cross-bow men discharged their bolts. It also signified a projecting turret, otherwise called a bartizan, such as is commonly seen in old castles.
Ballium. A term used in ancient military art, and probably a corruption of vallium. In towns, the appellation “ballium” was given to a work fenced with palisades, and sometimes to masonry covering the suburbs; but in castles, it was the space immediately within the outer wall.
Ballon. A town in the department of the Sarthe, France, formerly fortified; captured by the English in 1417; retaken by Charles VII. of France.