ABSTRACT
Later in the same year, Pascal and his father repeat at Rouen the experiment first conducted by Toricelli, and which consisted of inverting a tube of mercury, closed at the top end, into an open container, and noting that not all of the mercury flowed out of the tube. The traditional physics of Pascal's day argued that this was because nature had a 'horror of the void' and that it was this which prevented all the mercury from flowing down. Pascal mistrusted these explanations, and published, in October 1647, his Experiences nouvelles touchant Ie vide, in which he criticised the traditional view. This brought him into controversy with Father Noel, a Jesuit priest, and led him to conduct his famous experiment at the Puy-de-Dome on September 19th, 1648. He described this experiment in his Redt de la grande experience de l' equilibre des liqueurs in October of the same year, where he pointed out that, since the mercury came farther down the tube at the top of the Puyde-Dome than it did at the bottom, it was scarcely reasonable to argue that Nature's 'horror of the void' decreased whenever one went up a hill. These experiments involved Pascal in further controversy and are referred to on pp. 25, 27, and 179.
