View source for Delisle scale

{{Short description|Temperature scale}}
{{temperature}}
[[File:Joseph_Nicolas_Delisle_AGE_V11_1803.jpg | thumb | 220x124px | right | alt= Black and white drawing of Joseph Nicolas Delisle from 1803. He is facing slightly to the left. His hair appears to be grey curls or a wig. He is wearing a ruffled shirt. | Joseph-Nicolas Delisle]]
The '''Delisle scale''' is a [[temperature scale]] invented in 1732 by the French [[astronomer]] [[Joseph-Nicolas Delisle]] (1688&ndash;1768).<ref name="camuffo">{{cite book |last=Camuffo |first=Dario |title=Improved Understanding of Past Climatic Variability from Early Daily European Instrumental Sources|year=2002|publisher=Kluwer Academic Publishers|page=314}}</ref> The Delisle scale is notable as one of the few temperature scales that are inverted from the amount of [[thermal energy]] they measure; unlike most other temperature scales, higher measurements in degrees Delisle are colder, while lower measurements are warmer.{{efn|The [[Celsius]] temperature scale was also briefly "inverted" (with 0&nbsp;°C being the boiling point of water and 100&nbsp;°C being the freezing point) from its invention in 1742 until it was reversed in 1743 or 1744.}}

== History ==

In 1732, Delisle built a [[thermometer]] that used [[mercury (element)|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.<ref name="camuffo" /> Delisle thermometers usually had 2400 or 2700 gradations, appropriate for the winter in [[Saint Petersburg|St. Petersburg]],<ref>{{cite book|title= A history of the thermometer and its use in meteorology|url= https://archive.org/details/historythermomet00midd_055|url-access= limited|author=W. E. Knowles Middleton|year=1966|publisher= Johns Hopkins Press|page=[https://archive.org/details/historythermomet00midd_055/page/n51 88]}}</ref> as he had been invited by [[Peter I of Russia|Peter the Great]] to the city to found an observatory in 1725.<ref>{{cite book|title= History of Astronomy: An Encyclopedia |url= https://archive.org/details/historyofastrono00john |url-access= registration |editor=John Lankford|year=1997|page=[https://archive.org/details/historyofastrono00john/page/191 191]|publisher= Taylor & Francis |isbn= 9780815303220 }}</ref>  In 1738, [[Josias Weitbrecht]] {{nowrap|(1702&ndash;47)}} 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]].<ref name="camuffo" /> The [[Celsius]] 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]] and the manufacturer of Linnaeus thermometers, Daniel Ekström.<ref>{{cite web|url=https://web.archive.org/web/20210210064628/http://www.linnaeus.uu.se/online/life/6_32.html|editor=Gunnar Tibell|year=2008|work=Uppsala Universitet|title=Linnaeus' thermometer}}</ref>

The Delisle thermometer remained in use for almost 100 years in Russia.{{citation needed|date=July 2012}} One of its users was [[Mikhail Lomonosov]], who reversed it in his own work, measuring the freezing point of water as 0&nbsp;°D and the boiling point as 150&nbsp;°D.{{cn|date=June 2021}}

==Conversion table between the different temperature units==
{{Timeline Temperature Conversion}}

== See also ==
* [[Outline of metrology and measurement]]
* [[Conversion of scales of temperature]]

== Notes ==
{{Notelist}}

== References ==
{{Reflist}}

==External links==
*[https://www.scienceandsociety.co.uk/results.asp?image=10413117 Photo of an antique thermometer backing board c. 1758]&mdash;marked in four scales; the second is Delisle (spelled "de Lisle").

{{Scales of temperature}}
{{Portal bar|Energy}}

{{DEFAULTSORT:Delisle Scale}}
[[Category:Obsolete units of measurement]]
[[Category:Scales of temperature]]