Museo Galileo
Virtual Museum
Plate electrical machine
    • Setting:
      Room XIII
    • Maker:
    • Place:
    • Date:
      second half 18th cent.
    • Materials:
      wood, brass, glass
    • Dimensions:
      total height 605 mm; disk diameter 455 mm, thickness 5.6 mm
    • Inventory:
    • Plate electrical machine (Inv. 2705)

Plate frictional electrical machine. The glass disk is rotated by a simple crank and is rubbed by four small leather cushions slotted into the wooden uprights of the frame. The pressure of the two cushions on the crank side can be adjusted by two brass screws. The brass prime conductor, supported by a pillar, has two curved arms, each terminating in a concave disk with sharp points (the collectors), which end in close proximity to the surface of the glass disk. The amount of charge is controlled by the Lane discharging electrometer with vernier scale on its wooden support. Nearly all the machines of this type seen in European collections are English-made, usually from London. Provenance: Lorraine collections.