H TACKLE. A luff purchase. (_See_ WATCH-TACKLE.)

HALIBUT. A large oceanic bank fish, _Hippoglossus vulgaris_, weighing
from 300 to 500 lbs. particularly off Newfoundland; it resembles plaice,
and is excellent food, nor does it easily putrefy.

HALLEY'S CHART. The name given to the protracted curves of the variation
of the compass, known as the variation chart.

HALLIARDS, HALYARDS, OR HAULYARDS. The ropes or tackles usually employed
to hoist or lower any sail upon its respective yards, gaffs, or stay,
except the cross-jack and spritsail-yard, which are always slung; but in
small craft the spritsail-yard also has halliards. (_See_ JEERS.)

HALO. An extensive luminous ring including, the sun or moon, whose
light, passing through the intervening vapour, gives rise to the
phenomenon. Halos are called _lunar_ or _solar_, according as they
appear round the moon or sun. Prismatically coloured halos indicate the
presence of watery vapour, whereas white ones show that the vapour is
frozen.

HALSE, OR HALSER. Archaic spelling for _hawser_.

HALSTER. A west-country term for a man who draws a barge along by a
rope.

HALT! The military word of command to stop marching, or any other
evolution. A halt includes the period of such discontinuance.

HALVE-NET. A standing net used in the north to prevent fishes from
returning with the falling tide.

HALYARDS. _See_ HALLIARDS.

HAMACS. Columbus found that the inhabitants of the Bahama Islands had
for beds nets of cotton suspended at each end, which they called
_hamacs_, a name since adopted universally amongst seamen. (_See_
HAMMOCK.)

HAMBER, OR HAMBRO'-LINE. Small line used for seizings, lashings, &c.

HAMMACOE. Beam battens. (_See_ HAMMOCK-BATTENS.)

HAMMER. The shipwright's hammer is a well-known tool for driving nails
and clenching bolts, differing from hammers in general.

HAMMER, OF A GUN-LOCK. Formerly the steel covering of the pan from which
the flint of the cock struck sparks on to the priming; but now the cock
itself, by its hammer action on the cap or other percussion priming,
discharges the piece. Whether the hammer will be superseded by the
needle remains to be determined.

HAMMER-HEADED SHARK. The _Zygaena malleus_, a strange, ugly shark. The
eyes are situated at the extremities of the hammer-shaped head. They
seldom take bait or annoy human beings. They are for the most part
inert, live near the surf edge, and are frequently found washed up on
sandy beach