They are usually distinguished into breast-back-stays and after-back-stays; the intent of the former being to sustain the top-mast when the force of the wind acts upon the ship sideways, or, according to the sea-phrase, when the ship sails upon a wind; and the purpose of the latter is to enable it to carry sail when the wind is further aft.
There are also back-stays for the top-gallant-masts, in large ships, which are fixed in the same manner with those of the top-masts.
A pair of back-stays is usually formed of one rope, which is doubled in the middle, and fastened there so as to form an eye, which passes over the mast-head, from whence the two ends hang down, and are stretched to the channels by dead-eyes and laniards. See Dead-eyes, &c.
The figure of the back-stays, and their position, is exhibited in the article Rigging, to which the reader is further referred.
BADGE, bouteille, fausse galerie, in ship-building, a sort of ornament, placed on the outside of small ships, very near the stern, containing either a window, for the convenience of the cabin, or the representation of it: it is commonly decorated with marine figures, martial instruments, or such like emblems. See Quarter.
To BALANCE, (balancer, Fr.) to contract a sail into a narrower compass, in a storm, by retrenching or folding up a part of it at one corner; this method is used in contradistinction to reefing, which is common to all the principal sails; whereas balancing is peculiar to few, such as the mizen of a ship, and the main-sail of those vessels, wherein it is extended by a boom. See Boom and Reef.
The Balance of the mizen, fanon, is thus performed: the mizen-yard is lowered a little, then a small portion of the sail is rolled up at the peek, or upper corner, and fastened to the yard about one fifth inward from the outer end, or yard-arm, toward the mast. See Mizen.
A boom-main-sail is balanced, after all its reefs are taken in, by rolling up a similar portion of the hindmost, or aftmost lower-corner, called the clue, and fastening it strongly to the boom, having previously wrapped a piece of old canvas round the part (which is done in both cases) to prevent the sail from being fretted by the cord which fastens it.
BALLAST, lest, (ballaste, Dut. ballastro, Span.) a certain portion of stone, iron, gravel, or such like materials, deposited in a ship’s hold, when she has either no cargo, or too little to bring her sufficiently low in the water. It is used to counter-ballance the effort of the wind upon the masts, and give the ship a proper stability, that she may be enabled to carry sail without danger of over-turning.
There is often great difference in the proportion of ballast required to prepare ships of equal burthen for a voyage; the quantity being always more or less, according to the sharpness or flatness of the ship’s bottom, which seamen call the floor.