Otto von Guericke is most famous for his demonstration of the "Magdeburg hemispheres" in 1657. After joining two large copper hemispheres, he evacuated the resulting sphere with a vacuum pump of his own construction. Two teams of eight horses couldn't pull the hemispheres apart, demonstrating the powerful forces exerted by the atomosphere. When Guericke opened a valve letting in air, the hemispheres fell apart there on the courtyard in Magdeburg, Germany.
In 1663, Guericke invented the first electric generator for producing static electricity. It consisted of a large sphere of sulfur on a shaft that was turned with a crank. By rubbing the sphere with a cloth, a substantial static charge could be produced.
