No. 9 (2025): Issue № 9

On the Cover – The invention of the "Leyden jar".

Source: Privat-Deschanel A., Everett J.D. Elementary Treatise on Natural Philosophy. Part III: Electricity and Magnetism. New York: D. Appleton and Company, 1891, 609 p.

280 years ago in 1745, Dutch physicist Pieter van Musschenbroek from Leiden, along with his student Andreas Cunaeus, invented the "Leiden jar", the first capacitor. Trying to "condense" electricity from an electrophoretic machine in a vessel with water, the assistant received a powerful electric shock, from which he could not recover for several days. Scientists were interested in the case, and soon the first accumulators of electric charges appeared.