It says something about public interest in science during the seventeenth century that several of Clermont鈥檚 most prominent citizens insisted on joining Florin鈥檚 expedition. One can imagine the mayor, town clerk, priests, lawyers, merchants, and physicians jostling for the best position to see Florin make a baseline measurement of air pressure. Perhaps these middle-aged men also offered to carry some of the seven kilograms of mercury required. At the top of the Puy de D么me, Florin took another measurement. To his delight, and no doubt the delight of the assembled dignitaries, the air pressure at the summit was exactly that predicted by Torricelli鈥檚 theory 鈥
Bio:
Graeme Hunter is the author of Vital Forces: The Discovery of the Molecular Basis of Life (Academic Press) and Light Is a Messenger: The Life and Science of William Lawrence Bragg (Oxford University Press). This is the final essay in his Queen鈥檚 Quarterly series inspired by the four elements of classical antiquity. The previous instalments were published in QQ issues 127/4 (鈥淲ater鈥), 128/2 (鈥淥n the Rocks鈥), and 128/3 (鈥淎 Matter of Fire鈥).