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.he original Magdeburg hemispheres and Guericke's vacuum pump in the Deutsches Museum, Munich, Germany. The Magdeburg hemispheres, around 50 cm (20 inches) in diameter, were designed to demonstrate the vacuum pump that Guericke had invented.