This apparatus was made in 1879, which is remarkably late for an invention that took place as early as 1767 and of which Teylers Museum had already acquired a specimen in 1785. It involves the electrometer of the Englishman Thomas Lane. His invention was at the time one of the first attempts to measure static electricity.
The apparatus consists of a Leyden jar provided with a discharger with scale. The distance at which the discharge spark is generated can be adjusted. This distance serves as a measure for the electrostatically built voltage. Its maker, Johannes Aegidius Schoonbeek (1818-1899), started as amanuensis at the Teylers Museum in 1878, after working previously at the local Hogere Burgerschool (HBS: a former Dutch high school).
Electrometer, after Lane
1879