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 Sandøe Ørsted Anders Sandøe Ørsted Anders Sandøe Ørsted (21 December 1778, Rudkøbing – 1 May 1860) was a Danish lawyer, politician and jurist. He served as the Prime Minister of Denmark in 1853–1854. He studied philosophy and law at Copenhagen and was admitted to the bar in 1799. He became a noted jurist. An early case overseen by him was that of Hans Jonatan, an escaped slave, which was (at least viewed retrospectively) a major test case in Danish law on slavery; Anders condemned Hans to be returned to the West Indies, where he had been purchased (Hof-og Stadsret: "Generalmajorinde Henriette de