"The Armillary Sphere"

The armillary sphere was the principal instrument used by all mathematicians and astronomers to determine celestial positions before the 17^th century and the invention of the telescope.  The instrument was fashioned with interlocking and over lapping rings (armilla) which were moveable and adjustable for the seasons. The rings illustrated the circles of the sun, moon, known planets, and important stars. This engraving shows an armillary sphere designed for the Ptolemaic or earth centered cosmic system. 

Copperplate engraving, hand colored.
10 x 8 inches sheet size.
Excellent condition, printers crease lower left.