ORRERY

, an astronomical machine, for exhibiting the various motions and appearances of the sun and planets; and hence often called a Planetarium.

The reason of the name Orrery was this: Mr. Rowley, a mathematical instrument-maker, having got one from Mr. George Graham, the original inventor, to be sent abroad with some of his own instruments, he copied it, and made the first for the earl of Orrery, Sir Richard Steel, who knew nothing of Mr. Graham's machine, thinking to do justice to the first encourager, as well as to the inventor of such a curious instrument, called it au Orrery, and gave Rowley the praise due to Mr. Graham. Desaguliers' Experim. Philos. vol. 1, pa. 430. The figure of this grand Orrery is exhibited at fig. 1, pl. 19. It is since made in various other figures.