ClipArt ETC
An air pump, which removes air from an enclosed space. R is the receiver and space that it encloses is what it removes the air from. This particular model is a bell jar receiver. C is a pump cylinder, t is a bent tube connecting the two together, V and V' are valves.

Pneumatic Devices

An air pump, which removes air from an enclosed space. R is the receiver and space that it encloses…