De Leidsche Flesch: 100-year anniversary
Study association for Physics, Astronomy, Mathematics and Computer Science since 1923

This pendulum device was made by Johannes Joosten van Musschenbroek, an instrument maker from Leiden. He sold his instruments to Christiaan Huygens and Antoni van Leeuwenhoek, among others. The son of Jan van Musschenbroek, Pieter van Musschenbroek, is important in the history of our society. In 1746, he, or, according to the more popular story, his assistant, invented the first capacitor, which his colleague Abbé Nollet christened the Leyden jar.


The Leiden instrument-maker's workshop of the Van Musschenbroek family was a leading manufacturer of scientific instruments. The workshop was operational from 1660 to 1748. Many of the instruments have been retained and are kept at Rijksmuseum Boerhaave as part of the collection of instruments of Petrus van Musschenbroek, Leiden University and Willem Jacob ‘s Gravesande's Leiden Cabinet of Physics.