Italian physicist Evangelista Torricelli challenged two prevailing Aristotelian ideas in 1644—that air could not exert weight on Earth and that nature abhors a vacuum—with a novel experiment. In contrast to those conceptions, held by Torricelli’s mentor Galileo Galilei among others, the experiment proved that air has mass and that a stable vacuum can occur naturally. This 17th-century illustration by Gaspar Schott, a German Jesuit mathematician and science writer, combines aspects of Torricelli’s original apparatus with later variations built by contemporary scientists. It accompanies Schott’s commentary on advances in vacuum science in his 1664 Latin text Technica Curiosa, a copy of which is held at the Niels Bohr Library and Archives of the American Institute of Physics (publisher of Physics Today).
Glass tubes of various shapes and sizes, each sealed at one end, are filled with mercury and their open ends submerged in a mercury-filled vat. The mercury in...
