The water barometer

In the second half of the 17th and 18th centuries, the water barometer was an instrument for weather forecasts and had a large circulation in Europe. Its widespread use was thanks to the ability of the glass masters and the simplicity of its physical principles.

These principles are fundamentally the same ones as the Torricelli mercury barometer that we use today. The only difference between the two instruments is the fact that the atmospheric pressure survey in the water barometer is influenced by the possible range of the atmospheric temperatures. However it is surprising to notice that the water barometer, although conceptually simple, can also, under standard conditions, register the atmospheric pressure variations.