of quick-silvered glass, which
moves with the index, and is designed to reflect the image of the sun or
other object upon the horizon glass, whence it is again reflected to the
eye of the observer.

INDEX-ROD. A graduated indicator.

INDIAMAN. A term occasionally applied to any ship in the East India
trade, but in strict parlance the large ships formerly officered by the
East India Company for that trade, and generally armed.

INDIAN INK. Properly Chinese; compounded of a peculiar lamp-black and
gum.

INDIAN OCEAN. The great Oriental Ocean.

INDRAUGHT. A particular flowing of the ocean towards any contracting
part of a coast or coasts, as that which sets from the Atlantic into the
Straits of Gibraltar, and on other coasts of Europe and Africa. It
usually applies to a strong current, apt to engender a sort of vortex.

INDUCED MAGNETISM. The magnetic action of the earth, whereby every
particle of soft iron in certain positions is converted into a magnet.

INDULTO. The duty formerly exacted by the crown of Spain upon colonial
commodities.

INEQUALITY, SECULAR. A small irregularity in the motions of planets,
which becomes important only after a long lapse of years. The _great
inequality_ of Jupiter and Saturn is a variation of their orbital
positions, caused by the disturbing action of one planet on the other.

INERTIA. The passive principle by which bodies persist in a state of
motion or rest, and resist as much as they are resisted. (_See_ VIS
INERTIAE.)

INFANTRY. Foot soldiers of the regular army; so called throughout Europe
after the original Spanish "infanteria," or troops of the infanta or
queen of Spain, who first developed on a large scale the importance of
the arm.

INFERIOR CONJUNCTION. Mercury or Venus is said to be in inferior
conjunction, when it is situated in the same longitude as the sun, and
between that luminary and the earth.

INFERIOR PLANETS. This name, the opposite of superior, is applied to
Mercury and Venus, because they revolve in orbits interior to the
earth's path.

INFORMATION. In admiralty courts, implies a clause introduced into a
citation, intimating that in the event of a party cited not appearing,
the court will proceed in his absence.

INGS. An old word said to be left here by the Danes; it signifies low
grounds or springy meadows near a river, or creek, liable to occasional
overflowings.

IN-HAULER. The rope used for hauling in the clue of a boom-sail, or
jib-travell