von Guericke's Electrical Machine

The earliest form of electrical machine was devised by Otto von Guericke of Magdeburg in the early 18th century. it consisted of a globe of sulphur fixed on a spindle, and pressed with the dry surface of the hands while being made to rotate. He experimented with the production of electric sparks and with the attraction and repulsion of charged bodies. Sir Isaac Newton replaced the sulphur globe with one of glass. Various other improvements to the basic design were made, including the addition of a collector in the form of a metal tube held by a person standing on blocks of resin acting as an isulator, or more bizarrely by hanging them by silken cords. Winckler of Leipzig substituted a leather pad for the hands as a rubber. Gordon of Erfurth replaced the globe with a glass cylinder, and provided a collector in the form of a chain hung over the cylinder. Pointed collectors were not used until after the work of Benjamin Franklin. Nairne's cylinder machine was developed from this device.