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He had been invited to Russia by Peter the Great. In 1732 he 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. The Celsius scale too originally ran from zero for boiling water down to 100 for freezing water; in 1747 Linnaeus would invert the fixed points to give us the familiar scale.

The Delisle thermometers usually had 2400 graduations, appropriate to the winter in St. Petersburg. In 1738 Josias Weitbrecht ( 1702Events March 8 William III died; Princess Anne Stuart becomes Queen Anne of England, Scotland and Ireland. March 11 The first regular English language newspaper, The Daily Courant''. is published for the first time. May 4/ 14 The War of the Spanish Succes– 1747) recalibrated the Delisle thermometer with 0 degrees as the boiling point and 150 degrees as the freezing point of water. The Delisle thermometer remained in use for almost 100 years in Russia.

Thus, the unitThe word unit means any of several things: One, the first natural number. The natural or usual or smallest measure of something, of which there are multiples and of which there may be fractions. In most physical contexts, for example science and engineeri of this scale, the Delisle degree (sometimes spelled de Lisle), is -2/3 of a kelvinThe kelvin (symbol: K is the SI unit of temperature, and is one of the seven SI base units. It is defined by two facts: zero kelvin is absolute zero (when molecular motion stops), and one kelvin is the fraction 1/273. 16 of the thermodynamic temperature o (or a degree Celsius) and absolute zero is at 559.725 Delisle degrees.

1 See also

• Temperature conversion formulasSummary From kelvin From Celsius From Fahrenheit From Rankine From Delisle From Newton From Reaumur From Romer See also Conversion of units Physical quantity Thermodynamics.

2 External link

• Photo of an antique thermometer backing board c. 1758?—marked in four scales; the second is Delisle (spelled "de Lisle").