George III's double-barrelled air pump

1761

Air pump

1871-1900

Double-barrelled air pump, late 18th century.

1766-1795

Surface Condenser and Air Pump, England, 1775

1775

Single-barrelled air pump, late 18th century.

1770-1790

Double-barrelled air pump with bell jar by Dollond family

1780-1820