ar·mil·lar·y sphere (ärmə-lĕr′ē, är-mĭlə-rē)
An old astronomical model with solid, usually metal rings, all great circles of a single sphere, used to display relationships among the principal celestial circles.
[Translation of French sphère armillaire, from Latin armilla, bracelet, from armus, shoulder; see ar- in the Appendix of Indo-European roots.]
(click for a larger image)armillary sphere
by Adam Heroldt
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