2 articles for "Armillary Sphere"
Armillary Sphere [Astro*Index]An instrument used for calculating planetary positions and house cusps. De Vore has the inventor as Eratosthenes, Larousse as Thales or Anaximander. In any event, an armillary sphere is constructed with bands representing circles on the celestial sphere, connected along their diameters but free otherwise to rotate about each other to represent all the possible orientations of circles within a sphere.
See also:Armillary Sphere [DeVore]
♦ Celestial Sphere
A skeleton sphere suggested by concentric rings which represent the relative positions of the celestial circles of the equator and the ecliptic revolving within a horizon and meridian divided into degrees of longtitude and latitude. It was invented by Eratosthenes (q.v.) who by this means computed the size of the Earth, and inclination of the ecliptic to the equator; also the latitude of the city of Alexandria. The armillary sphere is frequently used as a decoration, such as the beautiful specimen cast in bronze and supported on the shoulders of Atlas, which adorns the entrance to Rockefeller Plaza in New York.
See also:
♦ Celestial Sphere
Astro*Index Copyright © 1997 Michael Erlewine