On this day, 324 years ago, on November 27, 1701 (October 28, 1701 in the lunar calendar), Swedish astronomer Anders Thurius was born. Anders Celsius (Swedish: ; November 27, 1701-April 25, 1744) was a Swedish astronomer. Sertius was born in Uppsala, Sweden. He was professor of astronomy at the University of Uppsala in Sweden from 1730 to 1744, and visited prominent astronomical observatories in Germany, Italy and France from 1732 to 1735. In 1733 he published a series of 316 aurora observations by himself and others between 1716 and 1732 at Nuremberg. In Paris he advocated measuring the length of an arc of the Lapland meridian, and in 1736 participated in an expedition prepared by the French Academy of Sciences for this purpose. Josephus founded the Uppsala Astronomical Observatory in 1741 and proposed the Celsius temperature scale in a paper to the Royal Swedish Academy of Sciences in 1742. Originally, his thermometer used the boiling point of water to be 0 degrees and the freezing point of water to be 100 degrees. Later, the scale was inverted by Karl Linne in 1745 and remains in use today. Anders Thersius was the first person in science to use and publish careful experiments to define the international temperature scale. In his paper "Observation of Two Continuous Degrees on a Thermometer" published in Swedish, he reported experiments to check whether the freezing point of water was independent of latitude (or atmospheric pressure). He determined the relationship between the boiling point of water and atmospheric pressure (which fits well with modern data). He also gave a law for measuring the boiling point if the air pressure is different from a certain standard air pressure. In 1744, he died of tuberculosis in Uppsala and was buried in the Old Uppsalakyrka Church. The Thorsius crater on the moon is named after him. Comments: Although he is an astronomer, the most famous one is a thermometer.