Gyrony

( Her.) Covered with gyrons, or formed of several gyrons, usually said of an escutcheon. Gyrophora, ( ji -rofō-ră,) n. (Bot.) A genus of lichens, several species of which po e nutritive prop erties, and are used as food in the arctic regions. They have been denominated tripe de roc he (rock-tripe). Gyroscope, n. [Gr. guros, a circle or rotation; skopeo, I perceive.) ( Astron.) An instrument which for a time attracted attention on account of its supposed capability of rendering visible the rotation of the earth on its axis. The apparatus was originally suggested by M. Foucault, but has since been materially modified. The principle on which its action depends was discovered about 1750, by Frisi, and enunciated by him as the Composition of Rotary Motion; and the object of the instrument is to exhibit the real composition of rotations about different axes impre ed at the same time on the same body. Thus, when a body is rotating about an axis, if any force tends to make it rotate about another axis, it will not rotate about either the old or the new axis, but about an intermediate one. In 1851, Signor Antinori, director of the museum at Florence, first brought the subject of the apparent displacement of the plane of vibration of the pendulum before the Academicians del Cimento; and on the 3d of February, in the same year, M. Foucault communicated his discovery to the Academy of Sciences at Paris, and experimentally proved the rotation of the earth by his well known pendulum experiment and his G. In the first case, if a pendulum is supposed to be suspended over either pole of the earth, and set in oscillation, it is evident that a spectator carried round by the rotation of the earth would so pa alternately under the two ends of the arc of the vibrating pendulum, that its plane of oscillation would appear to him to make a revolution from east to west in the same time as the earth revolves from west to east. If, then, the pendulum be supposed to be similarly suspended over the equator, it is evident that no change in the plane of oscillation can take place. But if the pendulum is suspended at any intermediate latitude, the rotation of the earth round the polar axis may be considered as the resultant of two rotations, one round an axis pa ing through the place of observation, and another round a perpendicular axis. The rotation about the latter axis cannot, however, affect the apparent motion of a pendulum suspended at the equator of that axis which is the great circle through the place of observation. The pendulum will, therefore, only be affected by a motion around the axis through the place, and this motion will vary as the sine of the latitude. The G., as an instrument, is an application of the principle in dynamics, that if a ma be set in motion freely in space, it will preserve its original plane of rotation, unle it be disturbed. M. Foucault presented his account of the G. to the Academy of Sciences in 1852; and in his apparatus there is a fixed plane below which the earth turns, and as the spectator is carried with it, causes it to appear to him as if the plane of the disc actually revolved. The experiments which can be performed with the G. illustrate the following principles: First, that matter in motion, as well as matter at rest, po e es inertia. Secondly, that the power po e ed by the shots from rifled guns to resist the force of gravity, is due to the gyratory motion given to the ball. Thirdly, the orbital and axial motions are connected intimately, and mutually affect each other's speed. Fourthly, that the apparent stable equilibrium of bodies not stable, as of a spinning-top asleep, is due to their rotation. Gyrose, ( ji'rōs ,) a. Bent like a crook. -v. a. To shackle; to chain; to fetter. Gyrostemoʻneæ, n . pl . [Gr. guros , round, and stem on, filament.] ( Bot .) A small order of plants, closely allied to the Euphorbiacese. It is distinguished from that order by having unisexual flowers, the carpels arranged round a central column, two suspended seeds in each carpel, and a hooked embryo. The uses of these plants are not known. Gyulai, a town of Hungary, in the co. of Bekes, 16 m. N.W. of Zarand. Manuf . Oil and wine. Pop . 18,000. Gyve, (jiv, n. [W. gefyn, a fetter.] A shackle for the leg; (mostly used in the plural.) IMG:content-0474.png:[graphic] GADS The American Dictionary and Cyclopedia GALL dian and Washita rivers. Surface , undulating; soil , fertile, red sandy loam. Products , corn, wheat, cotton and potatoes. Stock raising is the chief occupation. Cap. Arapahoe. Pop . (1897) about 6,000. Ga/belentz, von der, HANS CONON, philologist, born at Altenburg, Germany, Oct. 13, 1807; studied at Leipzig and Göttingen, making a specialty of the Chinese, Arabic, and Finno-Tartaric languages. He was familiar with eighty languages, and published: Elements de la Grammaire Mandschoue; Die Me lane is chen Sprachen; and a Manchou translation of the Chinese works, Sse - chu , Shu- king and Shi - king , besides other works. Died in Sept., 1874.