Mercury-in-glass thermometer related to the rapid cooling (and contraction) of the glass. When Celsius decided to use his own temperature scale, he originally defined his scale "upside-down", i.e. he chose to set the boiling point of pure water at 0 °C (212 °F) and the freezing point at -100 °C (-32 °F). One year later, Frenchman Jean-Pierre Christin proposed to invert the scale with the freezing point at and the boiling point at . He named it Centigrade (100 grades). Finally, Celsius proposed a method of calibrating a thermometer: These points are adequate for approximate calibration but both vary with atmospheric pressure.
Delisle scale of Linnaeus thermometers, Daniel Ekström. The Delisle thermometer remained in use for almost 100 years in Russia. One of its users was Mikhail Lomonosov, who reversed it, as Jean-Pierre Christin did with Celsius' scale, making the freezing point of water 0 °D and the boiling point 150 °D. Delisle scale The Delisle scale (°D) is a temperature scale invented in 1732 by the French astronomer Joseph-Nicolas Delisle (1688–1768). Delisle was the author of "Mémoires pour servir à l'histoire et aux progrès de l'Astronomie, de la Géographie et de la Physique" (1738). In 1732, Delisle built a thermometer that used mercury