The Eameses created this prototype for a Solar Do-Nothing Machine for Alcoa Forecast Collection in the late 1950's. It's a tabletopful of beautifully milled aluminum [naturally] pinwheels and cogs, all webbed together with tiny belts.
It's a lot of fun to watch and decipher, and though it's hard to capture in an image, it filmed really well. This is a still from a 2-min film on Vol. 6 of The Films of Ray and Charles Eames.