ing winds. These
however are mostly intertropical; the solar heat causing the sea-breeze
to blow on the land by day, and condensation and greater heat of the sea
causing a reaction when the land has cooled to a lower temperature.

ALTERNATION OR PERMUTATION OF QUANTITIES, is the varying or changing
their order, and is easily found by a continual multiplication of all
numbers.

ALTIMETRY. Trigonometry; the art of measuring heights or depressions of
land, whether accessible or not.

ALTITUDE. The elevation of any of the heavenly bodies above the plane of
the horizon, or its angular distance from the horizon, measured in the
direction of a great circle passing through the zenith. Also the third
dimension of a body, considered with regard to its elevation above the
ground.--_Apparent altitude_ is that which appears by sensible
observations made on the surface of the globe.--_Altitude of the pole._
The arc of the meridian between the pole of the heavens and the horizon
of any place, and therefore equal to its geographical latitude.--_Altitude
of the cone of the earth's and moon's shadow_, is the height of the one
or the other during an eclipse, and is measured from the centre of the
body.--_Altitude of a shot or shell._ The perpendicular height of the
vertex of the curve in which it moves above the horizon.--_Meridian
altitude._ The arc of the meridian,--or greater or less altitude,
measured from the horizon, of a celestial object in its passage over the
meridian, above or below the pole, of the place of the observer. In
Polar regions two such transits of the sun, and in England similarly,
circumpolar stars afford double observations for the determination of
time or latitude. The general term is understood by seamen to denote
mid-day, when the passage and meridian altitude of the sun affords the
latitude.--_True altitude_ is that produced by correcting the apparent
one for parallax and refraction.

ALTMIKLEC. A silver Turkish coin of 60 paras, or 2_s._ 9-1/2_d._
sterling.

ALUFFE, OR ALOOF. Nearer to the wind. This is a very old form of _luff_;
being noticed by Matthew Paris, and other writers, as a sea-term. (_See_
LUFF.)

ALURE. An old term for the gutter or drain along a battlement or parapet
wall.

ALVEUS. A very small ancient boat, made from the single trunk of a tree.
A monoxylon, or canoe.

A.M. The uncials for _ante-meridian_, or in the forenoon. (_See_
MERIDIAN.)

AMAIN [Saxon _a_, and _maegn_, force, s