Fortin barometer

[ fawr-tan; French fawr-tan ]
/ ˈfɔr tæn; French fɔrˈtɛ̃ /

noun

an adjustable cistern barometer, the most common of those employing mercury.

Origin of Fortin barometer

1870–75; named after J. Fortin (1750–1831), French physicist who invented it