Air pressure experiment. Paired evacuated rubber seals (versions of the Magdeburg hemispheres) inside an air-filled vacuum chamber. The vacuum between the two rubber seals means that they cannot be pulled apart without using great force, because the weight of the atmosphere is pressing them together. However, if the air in the vacuum chamber is evacuated (see image C011/1406), then the two rubber seals will fall apart as the atmospheric pressure keeping them together is lost. The gauge at upper centre records the pressure.
Model release not required. Property release not required.