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
Uppsala University the previous century, but eventually a larger emphasis on sciences and practically useful knowledge developed. The innovative mathematician and physicist Samuel Klingenstierna (1698–1765) was made a professor in 1728, the physicist and astronomer Anders Celsius in 1729, and Carl Linnaeus was made professor of Medicine with Botany in 1741. The university was not immune to the parliamentary struggle between the parties known as the "Hats" and the "Caps", with the former having a preference for hard sciences and practical knowledge. The Hat government then in power established a chair in economics ("Œconomia publica") in 1741 and called Anders Berch as