Engraving of Evangelista Torricelli (1608-1647). In 1641, Galileo Galilei (1564-1642) invited Torricelli to become his personal asistance on the strength of the latter's 'Trattato del Moto', published in 1641. At Galileo's death, Torricelli succeeded him as profesor of mathematics and philosophy at Florence, Italy. In 1643, his experiments with vacuums and presure led to him inventing the mercury barometer (or 'torricelli tube') and he greatly improved telescopes and microscopes.
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