CELSIUS, ANDERS 0701-1744), Swedish astronomer, was born, on Nov. 27, 170 1, in Uppsala, where he was professor of astronomy (I 730-44). At Nuremberg he published in 1733 a col lection of 316 observations of the aurora borealis made by himself and others 1716-32. In Paris he advocated the measurement of an arc of the meridian in Lapland, and took part, in in the expedition organized for the purpose by the French Academy. Six years later he described the centigrade thermometer in a paper read before the Swedish Academy of Sciences (see THERMOM ETRY). Celsius died at Uppsala on April He wrote : Nova Methodus distantiam solis a terra determinandi (173o) ; De obser vationibus pro figura telluris determinanda (1738) ; besides many less important works. The centigrade thermometer is often called the Celsius thermometer, as other thermometers are named after Fahrenheit and Reaumur.
See W. Ostwald's Klassiker der exacten Wissenschaften, No. 57 (Leipzig, 1904), where Celsius's memoir on the thermometric scale is given in German with critical and biographical notes.