Large electrostatic generator with Leyden jars, after Van Marum

This apparatus is the largest flat-plate electrostatic generator of the world. The instrument was made following the instructions of Martinus van Marum, the man who actually build up the Teylers Museum. As a true 18th century man, he was fascinated by the at that time popular static electricity. During his student days he had already designed an electrostatic generator. Supported by the large funds of Teylers Museum, he seized the opportunity to make the largest generator of his time. He hoped to make discoveries that were thought impossible when using smaller machines. Static electricity can be generated by friction during the time the glass plates rotate. In combination with the Leyden jars, unprecedentedly large sparks were generated. After the discovery of the battery in 1800, the instrument did not play an important part anymore.

A literally shocking experience. That was what the Leyden professor Van Musschenbroek experienced, when he accidentally invented the electrical capacitor in 1746. ‘Nothing in the world can seduce me to repeat this experiment’ he is said to have exclaimed. At that time electricity was assumed to be a liquid. An assistant had tried to collect this ‘fluid’ in a jar. The shock that followed announced the birth of the ‘Leyden jar’, or the capacitor. Such a capacitor can double electric charges and hold them for a while. You need: two conductors, one connected to earth, and an insulating layer in between them. A charge at one side generates an equally large, but opposite, charge at the other side. The Leyden jars in the Teylers Museum are amongst the largest ones ever made.