Gasparo Berti

Gasparo Berti (about 1600 to 1643) was an Italian mathematician, astronomer and physicist, probably born in Mantua, who spent most of his life in Rome. He is most famous for an experiment in which he unknowingly created the first working barometer. Though best known for mathematics and physics, little of his work in either survives. In 1630 Giovanni Battista Baliani wrote to Galileo that his siphon could not raise water more than about 10 metres, and Galileo proposed that a vacuum held the water up. When Galileo's Two New Sciences reached Rome in December 1638, Berti and Father Raffaello Magiotti set out to test whether a vacuum could be produced, and Magiotti devised the experiment. It took place between 1639 and 1643, in the presence of Berti, Magiotti, Athanasius Kircher and probably Niccolò Zucchi. Berti built an 11 metre lead tube, filled it with water, sealed both ends, set one end in a basin of water and unsealed it. Some of the water flowed out, but much stayed, filling the tube to about 10 metres above the basin. He died before January 1644.