Purpose
To have students manually sense atmospheric pressure

Description
Evacuate Magdeburg hemispheres with a hand pump and have a student try to separate them.
1. Beforehand: Check seals for dirt &/or other debris. Reapply minimal vacuum grease to gaskets only if necessary. Attach hand pump to opened valve.
2. Press the two Madgeburg spheres together to ensure a complete contact between the rims.

Equipment
2 Madgeburg hemispheres, Hand-held Pump