armillary

[In Fr. armilla ire; Sp. armilar; Port. armillar; Ital. arm ill are; Low Lat. armil lari us; from Cla . Lat. armilla = an armlet, an arm-ring, a bracelet.] Resembling a bracelet in form; circular. (Rarely used, except in Astronomy.) "He [Hipparch us] is also said to have erected armil lary circles at Alexandria."-Penny Cycl., ii. 525. armillary sphere. Mech. & Astron.: A sphere not solid like a modern celestial globe, but consisting of several metallic or other circles mechanically fixed in such relative positions that one represented the celestial equator, a second the ecliptic, and two more the colures. It was capable of revolving on its axis within a movable horizon. Astronomers used the armillary sphere for purposes of instruction not merely in ancient times, but on to the age of Tycho Brahe, in the sixteenth century. Now, however, it has fallen into disuse, having been superseded by the celestial globe. [ASTROLABE, CELESTIAL.] "When the circles of the mundane sphere are supposed to be described on the convex surface of a sphere, which is hollow within, and, after this, you imagine all parts of the sphere's surface to be cut away, except those parts on which such circles are described; then that sphere is called an armillary sphere , because it appears in the form of several circular rings, or bracelets, put together in a due position."-Harris: Descrip tion of the Globes .