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
Anders Henrik Bull Anders Henrik Bull Anders Henrik Bull (25 January 1875 – after 1909) was a Norwegian electrical engineer. He was born in Minneapolis as the son of ophthalmologist Ole Bornemann Bull (1842–1916) and his first wife Marie Cathrine Lund (1843–1884). The family moved to Norway in 1876. He took his engineering education in Kristiania and Hannover. He returned to Norway from Hannover in 1901, and became noted in the engineering community for his pioneering work on wireless telegraphy. He also worked for Norsk Hydro, as a consultant to Kristian Birkeland, from 1906 to 1909, in that company's formative phase. He married