Otto von Guericke's Magdeburg Hemispheres and Air Pump

The two copper hemispheres at the bottom of the case are Otto von Guericke's originals, shown with his air pump in the Deutsches Museum in Munich. Guericke, the mayor of Magdeburg, fitted the halves together and pumped out the air, and teams of horses could not pull them apart, a public proof of how hard the atmosphere presses. Accounts date his demonstrations to the 1650s.