Museo Galileo
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Kinnersley electrometer
    • Setting:
      Room XI
    • Inventor:
      Ebenezer Kinnersley
    • Maker:
    • Place:
    • Date:
      late 18th cent.
    • Materials:
      brass, glass
    • Dimensions:
      total height 275 mm
    • Inventory:
    • Kinnersley electrometer (Inv. 421)

Electrometer, probably English-made, consisting of a glass tube with brass fittings and two electrodes, of which the upper is adjustable. A glass capillary tube is attached to the side. This is a simplified version of Ebenezer Kinnersley's "electrical air thermometer," which he described to his friend Benjamin Franklin in 1761. Colored water was poured into the airtight cylinder. A spark jumping between the two electrodes heated the air, which expanded, pushing the water up the capillary tube. This gave a crude measure of the electrical charge. Provenance: Lorraine collections.