Von Guericke's demonstration of the power of a vacuum. A platform was suspended from the bottom of an evacuated sphere made up of two copper hemispheres, and more and more weights were placed on it. One of a series of demonstrations made by von Guericke. From Experimenta Nova ut vocantur Magdeburgica De Vacuo Spatio (New Magdeburg Experiments About the Vacuum), Otto von Guericke, (Amsterdam, 1672). Engraving.