Medical thermometer Bahamas, Belize, and the Cayman Islands. Prominent Dutch mathematician, astronomer and physicist Christiaan Huygens created a clinical thermometer in 1665, to which he added an early form of the centigrade scale by setting the scale to the freezing and boiling points of water. By 1742 Swedish astronomer Anders Celsius created the Celsius temperature scale that was the reverse of the modern scale, in that "0" was the boiling point of water, while "100" was freezing. It would later be reversed by Swedish botanist Carolus Linnaeus (1707–1778) in 1744. Working independently of Celsius, the Lyonnais physicist Jean-Pierre Christin, permanent secretary of
Celsius formally adopted "degree Celsius" in 1948, formally keeping the recognized degree symbol, rather than adopting the gradian/centesimal degree symbol. For scientific use, "Celsius" is the term usually used, with "centigrade" remaining in common but decreasing use, especially in informal contexts in English-speaking countries. It was not until February 1985 that the weather forecasts issued by the BBC switched from "centigrade" to "Celsius". Some key temperatures relating the Celsius scale to other temperature scales are shown in the table below. The "degree Celsius" has been the only SI unit whose full unit name contains an uppercase letter since the SI base