Quick Answer: Magdeburg Hemispheres are two hollow hemispheres that join into a sealed sphere for demonstrating atmospheric pressure. Once the air inside is pumped out, outside air pressure holds them together so firmly that they are hard to pull apart.
Last updated: October 2026
Key Features
Two hollow hemispheres with matching sealing rims
Handles for pulling the hemispheres apart
Valve for vacuum connection and for letting air back in
Connects to a vacuum pump with rubber vacuum tubing
About This Product
Students join the hemispheres, pump out the air, close the valve and then try to pull them apart by the handles. The resistance shows the force of atmospheric pressure acting on the outside, and opening the valve to let air back in lets them come apart easily, which shows that the force comes from the pressure difference. Enquiries from Syria, Afghanistan, Saudi Arabia, Côte d'Ivoire, South Korea and United Arab Emirates for the Magdeburg’s hemispheres receive an export quotation.
Frequently Asked Questions
Why are the hemispheres hard to separate after the air is removed?
The pressure inside is lower than the atmospheric pressure outside, so the outside air presses the hemispheres together until air is let back in.
