Gustav Fechner's version of Bohnenberger's electrocope (Bohnenberger had two vertical piles turned in opposite directions):
1=A. Dry pile. B Anode. C Cathode. D. Gold foil. E. Glass hub. F. External contact.

When a charge is applied to F it spreads to the gold foil D, which is attracted to either B or C, depending on the sign of the applied charge.
Own work
Episcophagus