Meteorology known as the first "anemometer". In 1607, Galileo Galilei constructed a thermoscope. In 1611, Johannes Kepler wrote the first scientific treatise on snow crystals: "Strena Seu de Nive Sexangula (A New Year's Gift of Hexagonal Snow)". In 1643, Evangelista Torricelli invented the mercury barometer. In 1662, Sir Christopher Wren invented the mechanical, self-emptying, tipping bucket rain gauge. In 1714, Gabriel Fahrenheit created a reliable scale for measuring temperature with a mercury-type thermometer. In 1742, Anders Celsius, a Swedish astronomer, proposed the "centigrade" temperature scale, the predecessor of the current Celsius scale. In 1783, the first hair hygrometer was demonstrated by
Medical thermometer the "Académie des sciences, belles-lettres et arts de Lyon", developed a similar scale in which "0" represented the freezing point of water and "100" represented boiling. On 19 May 1743 he published the design of a mercury thermometer, the "Thermometer of Lyon" built by the craftsman Pierre Casati that used this scale. The medical thermometer was used by Dutch chemist and physician Hermann Boerhaave (1668–1738), as well as his notable students Gerard van Swieten (1700–72) and Anton de Haen (1704–76). It was also utilized around the same time by Scottish physician George Martine (1700–1741). De Haen made particular strides in