3B30.30-Bell Jar Vacuum


Description: This demonstration illustrates low pressure vs high pressure like in a hurricane.


  • Bell Jar
  • Glass water tray
  • Vacuum pump with tube
  • 2 Metal rectangles

Setup Procedure:

  1. Fill the glass tray 3/4 full of water
  2. Place the 2 metal rectangles about 3 inches from each other in the glass tray so that the bell jar can sit atop them
  3. Place the bell jar on top of the metal rectangles
  4. Attach the tube with black cork into the top of the bell jar and attach that to the vacuum pump

Demonstration Procedure 

  1. Turn the vacuum pump on until the water level rises to its maximum amount without bubbling up
  2. Turn the vacuum pump off and slowly release the pressure atop the bell jar by pulling the hose out of the vacuum pump