Fortin barometer A mercury barometer that requires the accurate setting of the mercury level at a fixed point (scale zero, see fiducial point). The reading of the mercury height is then taken by adjusting a vernier scale to the top of the mercury column. The barometer was invented early in the nineteenth century by Jean Fortin. See also Kew barometer.

Fortin barometer Mercury barometer that requires the accurate setting of the mercury level at a fixed point (scale zero, see FIDUCIAL POINT). The reading of the mercury height is then taken by adjusting a vernier scale to the top of the mercury column. See also KEW BAROMETER.