An orrery is a great mechanical contraption, a cosmic clockwork of sorts, that demonstrates the movements of the planets relative to each other.
I didn’t want to run a tiny thumbnail image because that would cheat you of seeing the intricate nature of the gears. You can find reproductions of this and other wonderous gizmos (astrolabes, tellurions, a heliochronometer) for sale here. (Why not give ’em a plug – I borrowed their photo.)
Orreries come in a variety of shapes and sizes. A particularly famous one is the Rittenhouse Orrery, which lives at UPenn.
Orrery also provides the title and the structure of an extraordinary book of poems by Richard Kenney, for which a detail of the Rittenhouse contraption serves as the cover. But the poetry itself touches only briefly on the orrery and mostly portrays memories of a few seasons on an aging cider-milling farm in Vermont. Evidently the book is out of print now, but you can still pick up a used copy via Amazon. A friend who was related in some way to the author gave me a copy. I love it, despite (or because of?) the fact that the vocabulary is WAY over my head. Of the two critics quoted on Kenney’s Wikipedia entry, one hated the book. Fine, for me it’s challenging and evocative.
I’ll just leave you with the shortest vignette in the book, a selection called Married:
on blue stones
where the great stained
butterflies the floor.