An armillary sphere is a device for studying the rotation of the earth and other astronomical bodies

(i think lol)

An armillary sphere is an instrument consisting of graduated metal circles used to represent the motions of celestial bodies around the earth.

J. S. Slater has written:

'Description of an improved armillary sphere'

it was either made in the date of 255 BC or 150 A.DI'm not sure (read it in books!)

Ancient people saw Saturn, including Claudius Ptolemy, who used an armillary sphere - a device made of metal rings - to track all of the stars and planets.