Delisle (°De) - Unit Information & Conversion
What is a Delisle?
Definition
The Delisle scale (°De) is a historical temperature scale where the boiling point of water is set at 0 degrees and the freezing point at 150 degrees. The scale decreases as thermal energy increases.
History
Invented by the French astronomer Joseph-Nicolas Delisle in 1732 for use in Russia. He defined his scale with the boiling point of water as 0 °De and the freezing point as 150 °De. It was used primarily in Russia for about a century.
Common Uses
- Historical Significance: Of interest in the history of thermometry, particularly in Russia.
- Not used in modern scientific or general applications.
Unit FAQs
What are the freezing and boiling points of water in Delisle?
Water boils at 0 °De and freezes at 150 °De. Note that the scale is inverted compared to Celsius or Fahrenheit.
Why does the Delisle scale decrease with increasing temperature?
Delisle set the boiling point of water as his zero reference and measured the contraction of mercury as it cooled, leading to higher numbers for colder temperatures.
How does Delisle relate to Celsius?
The relationship is °De = (100 - °C) × 3/2.
Delisle Conversion Formulas
To Celsius:
To Fahrenheit:
To Kelvin:
To Rankine:
To Réaumur:
To Rømer:
To Newton:
Convert Delisle
Need to convert Delisle to other temperature units? Use our conversion tool.