Scale of temperature the Swedish astronomer Anders Celsius (1701–1744), who developed a similar temperature scale two years before his death. The degree Celsius (°C) can refer to a specific temperature on the Celsius scale as well as a unit to indicate a temperature "interval "(a difference between two temperatures or an uncertainty). From 1744 until 1954, 0 °C was defined as the freezing point of water and 100 °C was defined as the boiling point of water, both at a pressure of one standard atmosphere. Although these defining correlations are commonly taught in schools today, by international agreement the unit "degree Celsius" and
Delisle scale 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 as a working fluid. Delisle chose his scale using the temperature of boiling water as the fixed zero point and measured the contraction of the mercury (with lower temperatures) in hundred-thousandths. Delisle thermometers usually had 2400 or 2700 gradations, appropriate to the winter in St. Petersburg, as he