VOLTA's INSTRUMENTS
STRAW ELECTROMETER

The electroscope was modified by Volta to create the electrometer. The former had straws, replaced in the latter by very light balls. (Sguario used pith balls from elder wood in 1746; Canton suggested cork balls in 1754). The balls were suspended on thread, silver wire (Cavallo, in 1770) or gold leaf (Bennet and de Saussure in 1787). Volta’s modifications were intended to make measurements of potential repeatable and comparable.

Operation
Description
Explanation