The invention of the barometer by Torricelli, c 1644.
© Science Museum / Science & Society Picture Library
Engraving made c 1875 of Italian physicist Evangelista Torricelli (1608-1647). In 1643, Torricelli experimented with vacuums to demonstrate that atmospheric presure determines the height to which a fluid will rise in a tube when inverted over the same liquid. This concept led to the development of the barometer. Illustration from 'Das Reich der Luft' (The kingdom of the air) adapted from the work of Camille Flammarion (1842-1925) by the German Wilhelm SchUtte (1826-1912) and published in Leipzig in 1875.