ord sometimes used to signify priming-powder.

AMPERES. An ancient vessel, in which the rowers used an oar on each side
at once.

AMPHIBIA. A class of animals which, from a peculiar arrangement of
breathing organs, can live either in water or on land. [Gr. _amphibios_,
having a double manner of life.] Hence _amphibious_.

AMPHIPRORAE. Ancient vessels, both ends of which were prow-shaped, so
that in narrow channels they need not turn.

AMPHISCII. The inhabitants of the torrid zone are thus denominated from
their shadow being turned one part of the year to the north and the
other to the south.

AMPHOTEROPLON. _See_ HETEROPLON.

AMPLITUDE. As a general term, implies extent. In astronomy, it is an arc
of the horizon intercepted between the true east or west points thereof,
and the centre of the sun, star, or planet, at its rising or setting. In
other words, it is the horizontal angular distance of a star from the
east or west points. It is eastern or ortive when the heavenly object
rises, and western or occiduous when it sets, and is moreover northern
or southern according to its quarter of the horizon.--_Amplitude_, in
gunnery, is the range or whole distance of a projectile, or the right
horizontal line subtending the curvilineal path in which it
moved.--_Amplitude_, in magnetism, is the difference between the rising
and setting of the sun from the east and west points, as indicated by
the mariner's or magnetic compass--which subtracted from the true
amplitude, constitutes the error of the compass, which is the combined
effect of variation and local deviation.

AMPOTIS. The recess or ebb of the tide.

AMRELL. An archaic orthography for _admiral_.

AMULET. A small relic or sacred sentence, preservative against disaster
and disease, appended to the neck by superstitious people: few Italian
or Spanish seamen are without them.

AMUSETTE. A kind of gun on a stock, like that of a musket, but mounted
as a swivel, carrying a ball from half a pound to two pounds weight.

AMY. A foreigner serving on board, subject to some prince in friendship
with us.

ANACLASTICS, OR ANACLATICS. The ancient doctrine of refracted light or
dioptrics.--_Anaclastic curves_, the apparent curves formed at the
bottom of a vessel full of water, or anything at great depths overboard
to an eye placed in the air; also the heavenly vault as seen through the
atmosphere.

ANADROMOUS. A term applied to migratory fishes, which have their stated
ti