2B30.30 - Magdeburg Plate
Demonstrate that atmospheric pressure is strong enough to keep two evacuated plates together.
Clamp down the flat plate with the o-ring in the groove using squeezee clamps. Then place the plate with the attached handle on top of the clamped down plate. Attach the syringe vacuum pump to the top plate. Make sure the valve is open for operation.
There is a show and tell version of this used by glass movers. Available upon request.
Instructions: The Magdeburg hemispheres plates are set of plates which fit together along an air tight edge (the o-ring). One plate has a fitting which allows it to be pumped down by the syringe vacuum pump and sealed off. Hook up the syringe to the fitting and make sure the valve is open. Pump down the set, close the valve and then disconnect the pump attachment.
Now ask one students to come up and try to pull apart the plates... They can't. Release the valve and the plates should then pop right apart.