Model diving bell with 12 sinking weights

Model diving bell with 12 sinking weights, unknown maker, before 1753. Once belonged to Stephen Demainbray.

This is a standard diving bell model of the mid-eighteenth century. It has twelve lead weights which kept it submerged. The wire cage was used to contain small birds or mice so that the bell could be seen in action. It once belonged to Stephen Demainbray and was used by him in his lecfures on natural philosophy. Demainbray worked as superintendent at the King's observatory at Kew from 1768 and his collection of instruments and apparatus was absorbed into the King's own collection.