Drum model bras orrery, 1781-1795.
© Science Museum / Science & Society Picture Library
Dated to the period between the discovery of Uranus (1781) and the death of its maker George Adams junior (1795), this planetary model is based on a design introduced in the mid 18th century by Benjamin Martin. Called an orrery or planetarium, it is a demonstration model to show the motions of the Earth, Moon and planets around the Sun. It has a bras drum base with pedestal stand and seven planets out to Uranus on long rod-arms. Such devices became popular during the 18th century when the Copernican theory was fully accepted. To reproduce the motions of the solar system this model employs a hand crank to drive gear wheels. This fine orrery would have been the property of a wealthy individual with an interest in astronomy.