Air pump and condenser, 1761.

This air pump by George Adams, instrument maker to the king, is the centrepiece of the pneumatics apparatus commisioned by George III in 1761. The arrangement of valves is copied from a pump made about 10 years earlier by John Smeaton, who later became famous as a civil engineer. The air pump can be used to remove air from a container - to show the effects of a vacuum, for example. Alternatively, it can be used to pump air into a container.