ABSTRACT
The development of Physics and Mechanics in the seventeenth century led to a radical transformation of Meteorology. The rise of inductive methods of studying natural phenomena, and the invention of the thermometer, barometer, and other meteorological instruments, opened the way towards an exact study of the atmosphere in place of the astrological predictions or mere weather-lore which had been accepted as the basis for forecasts in the Middle Ages. The seventeenth century saw the invention of numerous hygroscopes embodying most of the principles upon which such instruments can be constructed. The earliest hygrometer appears to have been made by the Accademia del Cimento, which, also busied itself with the improvement of thermometers. Robert Boyle’s formulation of the law connecting the volume and pressure of a quantity of gas gave rise to a series of attempts to ascertain to what height the atmosphere extends above the Earth’s surface, and how atmospheric pressure varies with the altitude.
