hen the sail is set. This, with three pairs of
shrouds, completes the rigging, the whole made of _coir_ rope. Several
of these vessels were fitted as brigs, after their arrival in Arabia,
and armed by the Arabs for cruising in the Red Sea and Arabian Gulf, as
piratical vessels. It was of this class of vessel that Tippoo Sultan's
navy at Onore consisted. The large dhows generally make one voyage in
the season, to the southward of Arabia; taking advantage of the
north-east monsoon to come down, and the south-west to return with an
exchange cargo. The Arabs who man them are a powerful well-grown people,
and very acute and intelligent in trade. They usually navigate their
ships to Bengal in perfect safety, and with great skill. This was well
known to Captain Collier and his officers of the _Liverpool_ frigate,
when they had the trial cruise with the Imam of Muscat's fine frigate in
1820.

DIACLE. An old term for a boat-compass.

DIAGONAL BRACES, knees, planks, &c., are such as cross a vessel's
timbers obliquely. (_See_ DIAGONAL TRUSSING.)

DIAGONAL RIBBAND. A narrow plank made to a line formed on the
half-breadth plan, by taking the intersections of the diagonal line with
the timbers. (_See_ RIBBANDS.)

DIAGONALS. A line cutting the body-plan diagonally from the timbers to
the middle line. Diagonals are the several lines on the draughts,
delineating the station of the harpings and ribs, to form the body by.

DIAGONAL TRUSSING. A particular method of binding and strengthening a
vessel internally by a series of riders and truss-pieces placed
diagonally.

DIAMETER. In geometry, a right line passing through the centre of any
circular figure from one point of its circumference to another.

DIAMETER, APPARENT. The angle which the diameter of a heavenly body
subtends at any time, varying inversely with its distance. The true is
the real diameter, commonly expressed in miles.

DIAMOND-CUT. _See_ RHOMBUS.

DIAMOND-KNOT. An ornamental knot worked with the strands of a rope,
sometimes used for bucket-strops, on the foot-ropes of jib-booms,
man-ropes, &c.

DIBBS. A galley term for ready money. Also, a small pool of water.

DICE. _See_ DYCE.

DICHOTOMIZED. A term applied to the moon, when her longitude differs 90
deg. from that of the sun, in which position only half her disc is
illuminated.

DICKADEE. A northern name for the sand-piper.

DICK-A-DILVER. A name for the periwinkle on our eastern coasts.

DICKER-WORK. T