a wood, defile, or narrow
pass. In military language, troops defile or march out from.

DECAGON. A plane geometrical figure that has ten equal sides, and as
many equal angles.

DECAMP, TO. To raise the camp; the breaking up from a place where an
army has been encamped.

DECEPTIO VISUS. Any extraordinary instance of deception to the sight,
occasioned by the effects of atmospheric media. (_See_ TERRESTRIAL
REFRACTION and MIRAGE.)

DECIMATION. The punishing every tenth soldier by lot, was truly
_decimatio legionis_.

DECIME. A small copper coin of France, equal to two sous, or one-tenth
of a franc.

DECK, TO. A word formerly in use for to trim, as "we deckt up our
sails."

DECK-BEAM KNEES. The same as _lodging-knees_.

DECK-BEAMS. _See_ BEAMS.

DECK-CARGO, otherwise _deck-load_ (which see).

DECK-CLEATS. Pieces of wood temporarily nailed to the deck to secure
objects in bad weather, as guns, deck-load, &c.

DECK-HOOK. The compass timber bolted horizontally athwart a ship's bow,
connecting the stem, timbers, and deck-planks of the fore-part; it is
part and parcel of the _breast-hooks_.

DECK-HOUSE. An oblong-house on the deck of some merchantmen, especially
east-country vessels, and latterly in passenger steamers, with a gangway
on each side of it. (Sometimes termed _round-house_.)

DECK-LOAD. Timber, casks, or other cargo not liable to damage from wet,
stowed on the deck of merchant vessels. This, with the exception of
carboys of vitriol, is not included in a general policy of insurance on
goods, unless it be specially stipulated.

DECK-NAILS. A kind of spike with a snug head, commonly made in a diamond
form; they are single or double deck-nails, and from 4 to 12 inches
long.

DECK-PIPE. An iron pipe through which the chain cable is paid into the
chain-locker.

DECK-PUMPS. In a steamer, are at the side of the vessel, worked with a
lever by manual power, to supply additional water. In a ship-of-war,
used for washing decks (one of the midship pumps).

DECKS. The platforms laid longitudinally over the transverse beams; in
ships of war they support the guns. The terms in use for these decks
are, assuming the largest ship of the line:--_Poop_, the deck which
includes from the mizen-mast to the taffrail. The _upper_ or
_spar-deck_, from stem to stern, having conventional divisions; as,
_quarter-deck_, which is, when clear for action, the space abaft the
main-mast, including the cabin; next, _the waist_,