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A prolate spheroid; a figure described by the revolution of an ellipse about its greater axis. Cf. Oblatum, and see Ellipsoid of revolution, under Ellipsoid.

the ancients to be inclosed one within another, and to carry the heavenly bodies in their revolutions.

The path described by a heavenly body in its periodical revolution around another body; as, the orbit of Jupiter, of the earth, of the moon.

Of or pertaining to an orbit. "Orbital revolution." J. D. Forbes. Orbital index (Anat.), in the skull, the ratio of the vertical height to the transverse width of the orbit, which is taken as the standard, equal to 100.

An apparatus which illustrates, by the revolution of balls moved by wheelwork, the relative size, periodic motions, positions, orbits, etc., of bodies in the solar system.

Generated by the revolution of a parabola, or by a line that moves on a parabola as a directing curve; as, a parabolic conoid. Parabolic conoid, a paraboloid; a conoid whose directing curve is a parabola. See Conoid. -- Parabolic mirror (Opt.), a mirror having a paraboloidal surface which gives for parallel rays (as t…

he same direction, and in all parts equally distant; as, parallel lines; parallel planes. Revolutions . . . parallel to the equinoctial. Hakluyt.

In France, before the Revolution of 1789, one of the several principal judicial courts. Parliament heel, the inclination of a ship when made to careen by shifting her cargo or ballast. -- Parliament hinge (Arch.), a hinge with so great a projection from the wall or frame as to allow a door or shutter to swing back fla…

act or state of passing through any space; as, the peragration of the moon in her monthly revolution. [Obs.] Sir T. Browne.

of time as limited and determined by some recurring phenomenon, as by the completion of a revolution of one of the heavenly bodies; a division of time, as a series of years, months, or days, in which something is completed, and ready to recommence and go on in the same order; as, the period of the sun, or the earth, or…

Performed in a period, or regular revolution; proceeding in a series of successive circuits; as, the periodical motion of the planets round the sun.

lato was a warm advocate. -- Platonic year (Astron.), a period of time determined by the revolution of the equinoxes, or the space of time in which the stars and constellations return to their former places in respect to the equinoxes; -- called also great year. This revolution, which is caused by the precession of th…

a wheel on which prayers are pasted by Buddhist priests, who then put the wheel in rapid revolution. Each turn in supposed to have the efficacy of an oral repetition of all the prayers on the wheel. Sometimes it is moved by a stream.

hich was supposed to carry with it all the inclosed spheres with their planets in a daily revolution from east to west. See Crystalline heavens, under Crystalline. The motions of the greatest persons in a government ought to be, as the motions of the planets, under primum mobile. Bacon.

Note under Cycloid. -- Prolate ellipsoid or spheroid (Geom.), a figure generated by the revolution of an ellipse about its major axis. See Ellipsoid of revolution, under Ellipsoid.

A prolate spheroid. See Ellipsoid of revolution, under Ellipsoid.

The surface of constant negative curvature generated by the revolution of a tractrix. This surface corresponds in non-Euclidian space to the sphere in ordinary space. An important property of the surface is that any figure drawn upon it can be displaced in any way without tearing it or altering in size any of its eleme…

Backward tendency or movement after revolution, reform, or great progress in any direction. The new king had, at the very moment at which his fame and fortune reached the highest point, predicted the coming reaction. Macaulay. Reaction time (Physiol.), in nerve physiology, the interval between the application of a stim…

One who favors reaction, or seeks to undo political progress or revolution.

it., one who has been reconcentrated; specif., in Cuba, the Philippines, etc., during the revolution of 1895-98, one of the rural noncombatants who were concentrated by the military authorities in areas surrounding the fortified towns, and later were reconcentrated in the smaller limits of the towns themselves.…