An early 19th-Century "Ramsden" pattern electrostatic plate machine,

細節
An early 19th-Century "Ramsden" pattern electrostatic plate machine,
unsigned, the shaped mahogany platform base with twin supports incorporating the twin sets of friction pads, axis with 22in. (56cm.) diameter glass plate with rosewood mounted winding handle, the tubular conductor with twin combs, raised on glass insulators; with two leyden jars -- 17½in. (44.5cm.) long

See Colour Plate 1
(3)