Von Guericke, an engineer, was intrigued by current investigations into the nature of the atmosphere.
He decided to demonstrate the power of atmospheric pressure by showing its effect on a container that he had emptied of air - in other words, one that contained a vacuum.
And so he built a vacuum pump, rather like a water pump except that instead of removing water it removed air.
Von Guericke had a strong streak of the showman in him, and he demonstrated the powers of his pump and of the atmosphere too, with some spectacular stunts.
The one that gave him his reputation as a magician was mounted at Magdeburg before Emperor Ferdinand III and his court.
Von Guericke had built two copper hemispheres, 510 mm (20 in) in diameter, each with a flange so accurately finished that, when the two were greased and fitted together they formed a single, airtight sphere.
He pumped the air out of this, and then harnessed a team of eight horses to each hemisphere to try to pull them apart - without success.
As soon as he let the air into the sphere again, the two halves separated easily.
In another demonstration, he pumped the air out of a large vertical cylinder fitted with a piston.
Fifty men held ropes attached via pulleys to the piston and, as the air left the cylinder, the piston sank - until the 50 men were dangling in the air.
Twenty years later, the people of Magdeburg were astonished again by von Guericke 's magical powers, when he built a water barometer attached to the side of his house.
It was a brass tube over 9 m (30 ft) high, with a sealed glass section at the top.
Passersby would see a tiny figure of a man floating high in the glass when the weather was fine, and sinking out of sight as storms approached.