Otto von Guericke was a German scientist, inventor, and politician. His major scientific achievements were the establishment of the physics of vacuums, the discovery of an experimental method for clearly demonstrating electrostatic repulsion, and his advocacy of the reality of "action at a distance" and of "absolute space".

The Magdeburg hemispheres are a pair of large copper hemispheres, with mating rims. They were used to demonstrate the power of atmospheric pressure. When the rims were sealed with grease and the air was pumped out, the sphere contained a vacuum and could not be pulled apart by teams of horses.

Guericke's demonstration was performed on 8 May 1654 in front of the Imperial Diet, and the Emperor Ferdinand III in Regensburg. Thirty horses, in two teams of fifteen, could not separate the hemispheres until the valve was opened to equalize the air pressure. In 1656 he repeated the demonstration with sixteen horses (two teams of eight) in his hometown of Magdeburg, where he was mayor. He also took the two spheres, hung the two hemispheres with a support, and removed the air from within. He then strapped weights to the spheres, but the spheres would not budge. Gaspar Schott was the first to describe the experiment in print in his Mechanica Hydraulico-Pneumatica (1657). In 1663 (or, according to some sources, in 1661) the same demonstration was given in Berlin before Frederick William, Elector of Brandenburg with twenty-four horses.... More • http://en.wikipedia. ... n_Guericke View • Books • Images • Videos • Search Related • Inventors • Statesmen • Atmosphere • Enlightenment • Germany • November 20 • Physicists • Scorpio • 17th Century • Icons • People