Orrery planetary model by Newton & Co., 1851-1856

Dated to the middle of the nineteenth century this planetary model was made by the London instrument makers Newton and Company. Called an orrery or planetarium, it is a demonstration model to show the motions of the Earth, Moon and planets around the Sun. This example has a wooden base with paper calendar scales and eight planets out to Neptune on long rod-arms. Such devices became popular during seventeenth century especially after Sir Isaac Newton published his universal theory of gravity. To reproduce the motions of the solar system this model employs a hand crank to drive gear wheels. Models of this sort were commonly employed in schools or colleges to teach astronomical principles.