Barometer
![Mercury barometers from the Musée des Arts et Métiers, Paris](/Images/godic/202501/26/Old-barometers4640.jpg")
![](/Images/godic/202501/26/BernoullisLawDerivationDiagram.svg4640.png")
![Goethe's device](/Images/godic/202501/26/Barometer_Goethe_014641.jpg")
![Schematic drawing of a simple mercury barometer with vertical mercury column and reservoir at base](/Images/godic/202501/26/MercuryBarometer.svg4641.png")
A barometer is a scientific instrument used in meteorology to measure atmospheric pressure. Pressure tendency can forecast short term changes in the weather. Numerous measurements of air pressure are used within surface weather analysis to help find surface troughs, high pressure systems and frontal boundaries.