Discovery of the Leyden Jar, 1746
An accident in a laboratory in Leyden attracted popular attention the year before Franklin began his electricity experiments. Cuneus, a student, was using a Hauksbee machine to electrify water in a flask which he was holding in his hand. When the charge had been going for some time, he tried with his free hand to remove the chain which hung down through the neck of the bottle into the water. On touching the chain he received a shock so intense he almost died. A primitive form of frictional machine was invented around 1663 by Otto von Guericke, using a sulphur globe that could be rotated and rubbed by hand. Francis Hauksbee improved the basic design, with his frictional electrical machine that enabled a glass sphere to be rotated rapidly against a woolen cloth. This image has been color-enhanced
