User:R1F4T/sandbox/1

Procedure
The experiment uses a simple barometer to measure the pressure of air, filling it with mercury up until 75% of the tube. Any air bubbles in the tube must be removed by inverting several times. After that, a clean mercury is filled once again until the tube is completely full. The barometer is then placed inverted on the dish full of mercury. This causes the mercury in the tube to fall down until the difference between mercury on the surface and in the tube is about 760 mm. Even when the tube is shaken or tilted, the difference between the surface and in the tube is not affected due to the influence of atmospheric pressure.