The Delisle scale is a
temperature scale
Scale of temperature is a methodology of calibrating the physical quantity temperature in metrology. Empirical scales measure temperature in relation to convenient and stable parameters, such as the freezing and boiling point of water. Absolute ...
invented in 1732 by the French
astronomer
An astronomer is a scientist in the field of astronomy who focuses their studies on a specific question or field outside the scope of Earth. They observe astronomical objects such as stars, planets, natural satellite, moons, comets and galaxy, g ...
Joseph-Nicolas Delisle
Joseph-Nicolas Delisle (; 4 April 1688 – 11 September 1768) was a French astronomer and cartographer.
Life
Joseph was born in Paris, one of the 11 sons of Claude Delisle (1644–1720). Like many of his brothers, among them Guillaume 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'' (''Memories to Serve the History and Progress of Astronomy, Geography and Physics'') (1738). The Delisle scale is notable as one of the only temperature scales that is inverted from the amount of
thermal energy
The term "thermal energy" is used loosely in various contexts in physics and engineering. It can refer to several different well-defined physical concepts. These include the internal energy or enthalpy of a body of matter and radiation; heat, d ...
it measures; unlike most other temperature scales, higher measurements in degrees Delisle are colder, while lower measurements are warmer.
History
In 1732, Delisle built a
thermometer
A thermometer is a device that temperature measurement, measures temperature or a temperature gradient (the degree of hotness or coldness of an object). A thermometer has two important elements: (1) a temperature sensor (e.g. the bulb of a merc ...
that used
mercury
Mercury commonly refers to:
* Mercury (planet), the nearest planet to the Sun
* Mercury (element), a metallic chemical element with the symbol Hg
* Mercury (mythology), a Roman god
Mercury or The Mercury may also refer to:
Companies
* Merc ...
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
Saint Petersburg ( rus, links=no, Санкт-Петербург, a=Ru-Sankt Peterburg Leningrad Petrograd Piter.ogg, r=Sankt-Peterburg, p=ˈsankt pʲɪtʲɪrˈburk), formerly known as Petrograd (1914–1924) and later Leningrad (1924–1991), i ...
, as he had been invited by
Peter the Great
Peter I ( – ), most commonly known as Peter the Great,) or Pyotr Alekséyevich ( rus, Пётр Алексе́евич, p=ˈpʲɵtr ɐlʲɪˈksʲejɪvʲɪtɕ, , group=pron was a Russian monarch who ruled the Tsardom of Russia from t ...
to the city to found an observatory in 1725. In 1738,
Josias Weitbrecht Josias Weitbrecht (russian: Иосия Вейтбрехт, born 6 November 1702 in Schorndorf, died 28 February 1747 in St. Petersburg) was a German professor of medicine and anatomy in Russia.
Life and career
After his studies at the University of ...
recalibrated the Delisle thermometer with two fixed points, keeping 0 degrees as the boiling point and adding 150 degrees as the freezing point of water. He then sent this calibrated thermometer to various scholars, including
Anders Celsius
Anders Celsius (; 27 November 170125 April 1744) was a Swedish astronomer, physicist and mathematician. He was professor of astronomy at Uppsala University from 1730 to 1744, but traveled from 1732 to 1735 visiting notable observatories in Germa ...
.
The
Celsius
The degree Celsius is the unit of temperature on the Celsius scale (originally known as the centigrade scale outside Sweden), one of two temperature scales used in the International System of Units (SI), the other being the Kelvin scale. The ...
scale, like the Delisle scale, originally ran from zero for boiling water down to 100 for freezing water. This was reversed to its modern order after his death, in part at the instigation of Swedish botanist
Carl Linnaeus
Carl Linnaeus (; 23 May 1707 – 10 January 1778), also known after his ennoblement in 1761 as Carl von Linné Blunt (2004), p. 171. (), was a Swedish botanist, zoologist, taxonomist, and physician who formalised binomial nomenclature, the ...
and the manufacturer of Linnaeus thermometers, Daniel Ekström.
The Delisle thermometer remained in use for almost 100 years in Russia. One of its users was
Mikhail Lomonosov
Mikhail Vasilyevich Lomonosov (; russian: Михаил (Михайло) Васильевич Ломоносов, p=mʲɪxɐˈil vɐˈsʲilʲjɪvʲɪtɕ , a=Ru-Mikhail Vasilyevich Lomonosov.ogg; – ) was a Russian Empire, Russian polymath, s ...
, who reversed it in his own work, measuring the freezing point of water as 0 °D and the boiling point as 150 °D.
Conversion table between the different temperature units
See also
*
Comparison of temperature scales
This is a collection of temperature conversion formulas and comparisons among eight different temperature scales, several of which have long been obsolete.
Temperatures on scales that either do not share a numeric zero or are nonlinearly related c ...
Notes
References
External links
Photo of an antique thermometer backing board c. 1758mdash;marked in four scales; the second is Delisle (spelled "de Lisle").
{{DEFAULTSORT:Delisle Scale
Obsolete units of measurement
Scales of temperature