y for those bolts that are driven into the
hanging and lodging knees, drawn through the ship's sides, and termed
_in-and-out bolts_.

IN-BOARD. Within the ship; the opposite of _out-board_.

IN-BOATS! The order to hoist the boats in-board.

IN-BOW! The order to the bowman to throw in his oar, and prepare his
boat-hook, previous to getting alongside.

INCH. The smallest lineal measure to which a name is given; but it has
many subdivisions. Also, a general name for a small coast islet on the
northern shores, from the old Gaelic word.

INCIDENCE, ANGLE OF. That which the direction of a ray of light, &c.,
makes at the point where it strikes with a line drawn perpendicularly to
the surface of that body.

INCLINATION. In geometry, is the mutual tendency of two lines or planes
towards each other, so as to form an angle.

INCLINATION OF AN ORBIT. The angle which the path of a comet or planet
makes with the plane of the ecliptic.

INCLINATORY NEEDLE. An old term for the _dipping-needle_ (which see).

INCLINOMETER. An invention by Wales in Cook's second voyage, where
particulars are given.

INCOMPETENCY, OR INSUFFICIENCY, OF A MERCHANTMAN'S CREW. A bar to any
claim on warrantry; as it is an implied condition in the sea-worthiness
of a ship, that at sailing she must have a master of competent skill,
and a crew sufficient to navigate her on the voyage.

INDEMNIFICATION. A stipulated compensation for damage done.

INDEMNITY. Amnesty; security against punishment.

INDENTED LINE. In fortification, a connected line of works composed of
faces which offer a continued series of alternate salient and
re-entering angles. It is conveniently applied on the banks of a river
entering a town, and was to be seen on the James river in Virginia, near
Richmond, in 1864.

INDENTED PARAPET. One of which the interior slope is indented with a
series of vertical cavities, enabling the men stationed within them to
fire across the proper front.

INDENTING FOR STORES. An indispensable duty to show that every article
has been actually received.

INDENTURES, PAIR OF. A term for _charter-party_.

INDEX. The flat bar which carries the nonius scale and index-glass of a
quadrant, octant, quintant, or sextant.

INDEX-ERROR. The reading of the verniers of the above-named instruments.
It is the correction to be applied to the + or - reading of a vernier
when the horizon and index-glasses are parallel.

INDEX-GLASS. A plane speculum, or mirror