Museo Galileo
Virtual Museum
Single-barrel exhausting and compressing pump
    • Setting:
      Room XI
    • Maker:
    • Place:
    • Date:
    • Materials:
      mahogany, brass
    • Dimensions:
      total height 1300 mm, base 380x480 mm
    • Inventory:
    • Single-barrel exhausting and compressing pump (Inv. 1535)

Well-made pump with single upright barrel, mounted on a double wooden tripod. The piston is operated by means of a crank and rack. The base of the barrel is fitted with a valve. A pair of Magdeburg hemispheres is screwed onto the plate on the upper part of the machine. A three-way stop-cock allows the reversal of air inlet and delivery to the plate. The instrument could thus be used either as a vacuum pump or a compressor. For the latter purpose, the air was compressed in a special compartment. This innovation was described by John Smeaton in 1753. The pipe connecting the plate to the pump is a modern replacement. Provenance: Lorraine collections.