photo needed In existographies, Gasparo Berti (c.1600-1643) (CR:5), aka "Gaspar Berti" (Magiotti, 1650) was an Italian mathematician noted for his c.1639 water column vacuum experiment in which he set out to disprove the claim, found in Italian physicist Galileo Galilei’s 1632 Two New Sciences, that water could not be raised ‘a hair’s breath above 18 braccia’ (c. 11 meters). [1]

Overview
See main: Berti vacuum experiment
Galileo's ideas reached Rome in December of 1638 via 50 copies of his Two New Sciences, that quickly sold out. [2] Rafael Magiotti (c.1590-c.1658), owner of house depicted (below), and Gasparo Berti were excited by these ideas, and decided to seek a better way to attempt to produce a vacuum than with a siphon. Magiotti devised such an experiment, and sometime between 1639 and 1641, Berti (with Magiotti, Athanasius Kircher and Nicolo Zucchi present) carried it out. [3]

In Mar 1648, Rafael Magiotti, in a letter to Marin Mersenne (1588-1648), described how they upended a a large "lead siphon" c.22 braccia long that Berti had set up in the courtyard of his Magiotti's house. Magiotti claims that Berti, using the results of his experiments, managed to disprove Galileo's findings. [5]

In his first measurement, Berti measured from the bottom of the barrel, and hence measured a height well above 18 braccia, which gave him the initial conclusion that he had disproved Galileo. When it was point out to him, however, that he should have measured starting from the height of the water at the top—and not the bottom—of the barrel, he found the result exactly as Galileo had predicted. [2]

Reports by Athanasius Kircher and Gaspar Schott also describe Berti's experiments aimed at demonstrating the presence of the vacuum in a barometric tube. [5]
Berti experiment
Two different depictions of Italian mathematician Gasparo Berti's famous circa 1641 water tube vacuum testing experiment; the one to the right shown affixed to the house of Rafael Magiotti (c.1590-c.1658), who later described the experiment in a March 1648 letter to Marin Mersenne (1588-1648). [2]

Four total accounts of Berti's experiment exist, but a simple model to his experiment consisted of filling a long tube with water that had both ends plugged up, then placing the tube into a basin already full of water. The bottom end of the tube was opened, and the water that had begun inside of it poured out of the bottom hole into the basin. However, only part of the water in the tube flowed out, and the level of the water inside the tube stayed at an exact level, which happened to be thirty-four feet, the exact height Baliani and Galileo had observed that was limited by the siphon. What was most important about this experiment was that the lowering water had had left a space above it in the tube which had had no intermediate contact with air to fill it up. This seemed to suggest the possibility of a vacuum existing in the space above the water. [4]

In sum, Berti, in an attempt to prove Galileo wrong, affixed a metal tube some 22 braccia long to the side of a several story building, depicted adjacent—his findings proved Galileo correct.

Repercussion
The unwieldy size of the experiment led Italian physicist Evangelista Torricelli, in 1643, to redo the experiment, albeit using mercury, a denser than water fluid, which allowed for a smaller room-sized experimental device to be used.

References
1. (a) Braccio – Dictionary.com.
(b) Galilei, Galileo. (1838). Mathematical Discourses Concerning Two New Sciences: Relating to Mechanics and Local Motion (trans. John Weston). J. Hooke, 1730.
(c) Two New Sciences – Wikipedia.
2. Shea, William. (2003). Designing Experiments and Games of Chance: the Unconventional Science of Blaise Pascal (pgs. 24-26). Science History Publications.
3. Nature abhors a vacuum – UsingEnglish.com.
4. History of the barometer – Strange-Loops.com.
5. Gasparo Berti – Galileo Museum.

Further reading
● Burke, James. (1996). The Pinball Effect (pg. 133). Back Bay Books.

External links
● Gasparo Berti – Wikipedia.

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