service. Bonnet, in fortification, is a raised portion of the works at
any salient angle, having the same plan, but 10 or 12 feet more command
than the work on which it is based. It assists in protecting from
enfilade, and affords a plunging fire.

BONNET-FLOOK. A name of the well-known flat-fish, brill, pearl, or
mouse-dab; the _Pleuronectes rhombus_.

BONXIE. The Shetland name for the skua-gull (_Cataractes vulgaris_).
Also a very general northern term for sea-birds.

BONY-FISH. One of the names of the hard-head (which see).

BOOBY. A well-known tropical sea-bird, _Sula fusca_, of the family
_Pelecanidae_. It is fond of resting out of the water at night, even
preferring an unstable perch on the yard of a ship. The name is derived
from the way in which it allows itself to be caught immediately after
settling. The direction in which they fly as evening comes on often
shows where land may be found.

BOOBY-HATCH. A smaller kind of companion, but readily removable; it is
in use for merchantmen's half decks, and lifts off in one piece.

BOOK. A commercial term for a peculiar packing of muslin, bast, and
other stuffs.--_Brought to book_, made to account.

BOOKING. A reprimand.

BOOKS. (_See_ SHIP'S BOOKS.) Official documents.

BOOM. A long spar run out from different places in the ship, to extend
or boom out the foot of a particular sail; as, jib-boom, flying
jib-boom, studding-sail booms, driver or spanker boom, ringtail-boom,
main-boom, square-sail boom, &c. A ship is said to come booming forwards
when she comes with all the sail she can make. Boom also denotes a cable
stretched athwart the mouth of a river or harbour, with yards,
top-masts, or stout spars of wood lashed to it, to prevent the entrance
of an enemy.--_To top one's boom_, is to start off.--_To boom off_, to
shove a boat or vessel away with spars.

BOOMAGE. A duty levied to compound for harbour dues, anchorage, and
soundage.

BOOM-BOATS. Those stowed on the booms.

BOOM-BRACE PENDANT. A rope attached to the extremity of a studding-sail
boom, and leading down on deck; it is used to counteract the pressure of
the sail upon the boom.

BOOM-COVER. The tarpaulin, or painted, cover over the spars.

BOOMING. Sound of distant guns; it is often, but wrongly, applied to the
hissing or whistling of shot.

BOOM-IRONS. Are metal rings fitted on the yard-arms, through which the
studding-sail booms traverse; there is one on each top-sail yard-arm,
but on