Made of flexible synthetic rubber, this is a much simpler, easier to use, version of the original Magdeburg Hemispheres. Just press the two hemispheres firmly together (finger grips to the outside), which causes the air to be pushed out from between them. Grip each one tightly, and then see if you can separate them from each other! Just what, exactly is holding the two hemispheres together? The power of air pressure! To release the vacuum, simply pull back on one of the rubber release posts, allowing air to penetrate between the two hemispheres.

Both hemispheres measure approximately 3.25 inches (83mm) in diameter, and can be used individually on a flat surface, or with each other, to demonstrate a vacuum and air pressure.

Originally a pair of large copper hemispheres that were sealed with grease, the featured a valve to pump out the air and create a vacuum. Designed in 1650 by the German scientist Otto Von Guericke, in the town of Magdeburg. It was demonstrated in 1654 for Emperor Ferdinand III, using 30 horses, in two teams of 15. The animals were unable to separate the hemispheres, until the vacuum was released.

A teacher’s guide is included.