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 Celsius scale at the triple point of Vienna Standard Mean Ocean Water (VSMOW, 273.16 K and 0.01 °C), and at absolute zero (0 K and −273.15 °C), is that neither the melting nor boiling point of water under one standard atmosphere (101.325 kPa) remains a defining point for the Celsius scale. In 1948 when the 9th General Conference on Weights and Measures (CGPM) in Resolution 3 first considered using the triple point of water as a defining point, the triple point was so close to being 0.01 °C greater than water's known melting point, it was simply defined as precisely