Baroscope with Styrofoam sphere diameter 90mm and with scale
At a state of equilibrium the Baroscope is placed in a vacuum bell jar under atmospheric pressure.
When the air in the bell jar is then evacuated the Styrofoam sphere falls because of the reduction in lift.
Cleverly mounted on a balance beam base with a Styrofoam sphere attached at one end and an adjustable counterweight on the other end.
Styrofoam sphere diameter 90mm