BARREL-SCREW. A powerful machine, consisting of two large poppets, or male screws, moved by levers in their heads, upon a bank of plank, with a female screw at each end. It is of great use in starting a launch.
BARRICADE. A strong wooden rail, supported by stanchions extending as a fence across the foremost part of the quarter-deck, on the top of which some of the seamen's hammocks are usually stowed in time of battle. In a vessel of war the vacant spaces between the stanchions are commonly filled with rope-mats, cork, or pieces of old cable; and the upper part, which contains a double rope-netting above the sail, is stuffed with full hammocks to intercept small shot in the time of battle. Also, a temporary fortification or fence made with abatis, palisades, or any obstacles, to bar the approach of an enemy by a given avenue.
BARRIER of Ice. Ice stretching from the land-ice to the sea or main ice, or across a channel, so as to render it impassable.
BARRIER REEFS. Coral reefs that either extend in straight lines in front of the shores of a continent or large island, or encircle smaller isles, in both cases being separated from the land by a channel of water. Barrier reefs in New South Wales, the Bermudas, Laccadives, Maldives, &c.
BARRIERS. A martial exercise of men armed with short swords, within certain railings which separated them from the spectators. It has long been discontinued in England.
BARROW. A hillock, a tumulus.
BARSE. The common river-perch.
BARTIZAN. The overhanging turrets on a battlement.
BARUTH. An Indian measure, with a corresponding weight of 31⁄2 lbs. avoirdupois.
BASE. The breech of a gun. Also, the lowest part of the perimeter of a geometrical figure. When applied to a delta it is that edge of it which is washed by the sea, or recipient of the deltic branches. Also, the lowest part of a mountain or chain of mountains. Also, the level line on which any work stands, as the foot of a pillar. Also, an old boat-gun; a wall-piece on the musketoon principle, carrying a five-ounce ball.