A mechanical model of the solar system that represents the relative motions of the planets around the sun. More...
ETYMOLOGY: After Charles Boyle, 4th Earl of Orrery (1676-1731), who was given one of those models by John Rowley, a London instrument-maker. They were invented by George Graham c. 1700. The device would have been better named either after its inventor, Graham, or its maker, Rowley.
I've always been impressed with what people were able to accomplish with seemingly rudimentary tools in early times. Granted, this mechanism is based on the watch making trade. But they were still able to achieve some level of accuracy cutting all the gears needed to operate this model, all back in the 1700's.