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Temperature scale
Delisle temperature conversion formulae
|
from Delisle
|
to Delisle
|
Celsius
|
x
°De ? (100 ?
x
×
2
/
3
) °C
|
x
°C ? (100 ?
x
) ×
3
/
2
°De
|
Fahrenheit
|
x
°De ? (212 ?
x
×
6
/
5
) °F
|
x
°F ? (212 ?
x
) ×
5
/
6
°De
|
Kelvin
|
x
°De ? (373.15 ?
x
×
2
/
3
) K
|
x
K ? (373.15 ?
x
) ×
3
/
2
°De
|
Rankine
|
x
°De ? (671.67 ?
x
×
6
/
5
) °R
|
x
°R ? (671.67 ?
x
) ×
5
/
6
°De
|
For temperature
intervals
rather than specific temperatures,
1 °De =
2
/
3
°C = 1.2 °F
Conversion between temperature scales
|
The
Delisle scale
is a
temperature scale
invented in 1732 by the French
astronomer
Joseph-Nicolas Delisle
(1688–1768).
[1]
Delisle was the author of
Memoires pour servir a l'histoire et aux progres de l'Astronomie, de la Geographie 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 few temperature scales that is inverted from the amount of
thermal energy
it measures; unlike most other temperature scales, higher measurements in degrees Delisle are colder, while lower measurements are warmer.
[a]
History
[
edit
]
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.
[1]
Delisle thermometers usually had 2400 or 2700 gradations, appropriate for the winter in
St. Petersburg
,
[2]
as he had been invited by
Peter the Great
to the city to found an observatory in 1725.
[3]
In 1738,
Josias Weitbrecht
(1702–47)
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
.
[1]
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 Ekstrom.
[4]
The Delisle thermometer remained in use for almost 100 years in Russia.
[
citation needed
]
One of its users was
Mikhail Lomonosov
, who reversed it in his own work, measuring the freezing point of water as 0 °D and the boiling point as 150 °D.
[
citation needed
]
Conversion table between the different temperature units
[
edit
]
See also
[
edit
]
Notes
[
edit
]
- ^
The
Celsius
temperature scale was also briefly "inverted" (with 0 °C being the boiling point of water and 100 °C being the freezing point) from its invention in 1742 until it was reversed in 1743 or 1744.
References
[
edit
]
External links
[
edit
]