Otto von Guericke’s electrostatic generator, built around 1663–1667, was the first known friction-based machine to produce static electricity. The German inventor and scientist created it using a large globe of pure sulfur mounted on an axle, which could be rotated by hand and rubbed with a cloth or leather pad to generate charge through friction. This simple device produced visible sparks and demonstrated electrostatic attraction and repulsion, laying groundwork for later electrical experiments.

Design Features
The generator featured a sulfur sphere about 16 inches in diameter, encased in a wooden frame for support and rotation. A hand crank or manual turning mechanism spun the globe against a friction pad, typically dry cloth or skin, to triboelectrically charge the sulfur negatively while inducing positive charge elsewhere. Operators often stood on insulating platforms like resin blocks to enhance effects.

Historical Context
Guericke, also famed for his vacuum pump and Magdeburg hemispheres, experimented with the device in Magdeburg, Germany, showcasing repulsion of lightweight objects like feathers or water streams diverted by the charge. It predated glass-globe improvements by others like Francis Hauksbee and influenced 18th-century electrostatic machines. No original survives, but replicas use polycarbonate or resin balls for modern demos.

Visual Representations
Historical drawings depict the sulfur globe on a spindle within a box-like frame, with a figure rubbing the spinning sphere. Modern replicas show similar setups producing arcs to grounded conductors.