Search the Dictionary

An ideal surface, conceived as coinciding with, or containing, some designated astronomical line, circle, or other curve; as, the plane of an orbit; the plane of the ecliptic, or of the equator.

having a common radiating point; as, polar coördinates. Polar axis, that axis of an astronomical instrument, as an equatorial, which is parallel to the earths axis. -- Polar bear (Zoöl.), a large bear (Ursus, or Thalarctos, maritimus) inhabiting the arctic regions. It sometimes measures nearly nine feet in length and…

er. See under Range. -- Position micrometer, a micrometer applied to the tube of an astronomical telescope for measuring angles of position in the field of view. -- Single position (Arith.), the method of solving problems, in which the result obtained by operating with an assumed number is to the true result as the n…

gs without necessity; recklessly or viciously profuse; lavish; wasteful; not frugal or economical; as, a prodigal man; the prodigal son; prodigal giving; prodigal expenses. In fighting fields [patriots] were prodigal of blood. Dryden.

making provision to supply them; prudent in preparing for future exigencies; cautious; economical; -- sometimes followed by of; as, aprovident man; an animal provident of the future. And of our good and of our dignity, How provident he is. Milton.

Frugal; economical; not extravagant; as, a prudent woman; prudent expenditure of money.

Prussian; -- applied to certain astronomical tables published in the sixteenth century, founded on the principles of Copernicus, a Prussian.

One who accepts the astronomical system of Ptolemy.

A pinnate-leaved palm (Raphia ruffia) native of Madagascar, and of considerable economic importance on account of the strong fiber (raffia) obtained from its leafstalks.

The calculation of a ship's position, either from astronomical observations, or from the record of the courses steered and distances sailed as shown by compass and log, -- in the latter case called dead reckoning (see under Dead); -- also used fro dead reckoning in contradistinction to observation.

nsideration; reflective; contemplative; as, a reflecting mind. Reflecting circle, an astronomical instrument for measuring angless, like the sextant or Hadley's quadrant, by the reflection of light from two plane mirrors which it carries, and differing from the sextant chiefly in having an entire circle. -- Reflecting…

through the earth's atmosphere; -- hence distinguished as atmospheric refraction, or astronomical refraction.

A clock, or other timepiece, used as a standard of correct time. See Astronomical clock (a), under Clock.

Pertaining to, or designating, a set of astronomical tables computed by Kepler, and founded on the observations of Tycho Brahe; - - so named from Rudolph II., emperor of Germany.

A Chaldean astronomical period or cycle, the length of which has been variously estimated from 3,600 years to 3,600 days, or a little short of 10 years. Brande & C.

To avoid unnecessary expense or expenditure; to prevent waste; to be economical. Brass ordnance saveth in the quantity of the material. Bacon.

Avoiding unnecessary expense or waste; frugal; not lavish or wasteful; economical; as, a saving cook.

An astronomical instrument, the limb of which embraces a small portion only of a circle, used for measuring differences of declination too great for the compass of a micrometer. When it is used for measuring zenith distances of stars, it is called a zenith sector. Dip sector, an instrument used for measuring the dip of…

ers (Arith. & Alg.), those fractions whose denominators are some power of sixty; as, astronomical fractions, because formerly there were no others used in astronomical calculations. -- Sexagesimal, or Sexagenary, arithmetic, the method of computing by the sexagenary scale, or by sixties. -- Sexagesimal scale (Math.),…

, in which the heavenly bodies appear to have their places, and on which the various astronomical circles, as of right ascension and declination, the equator, ecliptic, etc., are conceived to be drawn; an ideal geometrical sphere, with the astronomical and geographical circles in their proper positions on it.…