Editing Barometer (section)

=== Berti's vacuum experiment ===
[[File:Gasparo Berti Experiment.jpg|thumb|198x198px|Gasparo Berti's experiment]]{{Main|Gasparo Berti#Berti's vacuum experiment}}
Galileo's ideas, presented in his ''Discorsi'' (''[[Two New Sciences]]''), reached Rome in December 1638.<ref name=":1">{{Cite book |last=Middleton |first=W. E. Knowles. |url=http://archive.org/details/historyofbaromet00midd |title=The history of the barometer |date=1964 |publisher=Baltimore, Johns Hopkins Press |pages=10}}</ref> Physicists [[Gasparo Berti]] and father [[Raffaello Magiotti]] were excited by these ideas, and decided to seek a better way to attempt to produce a vacuum other than with a siphon. Magiotti devised such an experiment. Four accounts of the experiment exist, all written some years later.<ref name=":1" /> No exact date was given, but since ''Two New Sciences'' reached Rome in December 1638, and Berti died before January 2, 1644, science historian W. E. Knowles Middleton places the event to sometime between 1639 and 1643.<ref name=":1" /> Present were Berti, Magiotti, [[Society of Jesus|Jesuit]] polymath [[Athanasius Kircher]], and Jesuit physicist [[Niccolò Zucchi]].<ref name="History of the Barometer" />

In brief, Berti's experiment consisted of filling with water a long tube that had both ends plugged, then standing the tube in a basin of water. The bottom end of the tube was opened, and water that had been inside of it poured out 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 {{convert|10.3|m|ft|abbr=on}},<ref>{{cite book |last=Gillispie |first=Charles Coulston |author-link1=Charles Coulston Gillispie |title=The Edge of Objectivity: An Essay in the History of Scientific Ideas |url=https://archive.org/details/edgeofobjectivit00char/page/99 |url-access=registration |year=1960 |publisher=Princeton University Press |isbn=0-691-02350-6 |pages=[https://archive.org/details/edgeofobjectivit00char/page/99 99–100] }}</ref> the same height limit Baliani had observed in the siphon. What was most important about this experiment was that the lowering water had left a space above it in the tube which 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.<ref name="History of the Barometer"/>