Orrery showing Sun, Earth & Moon by Thomas Wright, London early 18th century. Modified for display with wooden base (removed) and later separate pulley to drive wheelwork (removed).
Dated to the mid eighteenth century, this planetary model was made by the London instrument Maker Thomas Wright. Called an orrery or more correctly a tellurium, it is a demonstration model to show the motions of the Earth and Moon around the Sun. This example has a wooden drum base with a hand painted plate and brass calendar ring supported on pillars. 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. This type of orrery would have been commonly employed at public astronomy lectures.