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Temperature conversion for: Amonton, Barnsdorf, Beaumuir, Bergen, Brisson, Celsius, Cruquius, Dalencé, Dalton, De Luc, De Lyon, De la Hire, Delisle, Du Crest, Edinburgh, electron volts, Fahrenheit, Florentine I, Florentine II, Fowler, Hales, Hanow, Jacobs-Holborn, Kelvin, Kirch, La Court, Lange, Leyden, Ludolf, Miles, Murray, Newton, Paris, Poleni, Réaumur, Rømer, Rankine, Richter, Royal Society of London, Sagredo, Sulzer, and Wedgwood
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Behold, the ultimate temperature conversion machine!
A couple of weeks ago I stumbled across some charts from some eighteenth- and
nineteenth-century sources on the subject of thermometers and was intrigued with the
vast number of temperature scales that proliferated in those days. Most seem pretty
obscure now, but many at one time or another, such as that of the Royal Society of
London, enjoyed great popularity.
The systems of Anders Celsius (1701-1744); William Thomson, 1st Baron Kelvin
(1824-1907); and Daniel Gabriel Fahrenheit (1686-1736) ultimately prevailed, of
course, but you may have heard of a few others.
The scale established by René Antoine Ferchault de Réaumur
(1683-1757), in which freezing is zero and boiling is 80 degrees, still finds some
use among European cheesemakers and often shows up in nineteenth-century literature
such as Tolstoy’s War and Peace:
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Christmas came and except for the ceremonial Mass, the solemn and wearisome Christmas
congratulations from neighbors and servants, and the new dresses everyone put on, there
were no special festivities, though the calm frost of minus twenty degrees Réaumur, the
dazzling sunshine by day, and the starlight of the winter nights seemed to call for some
special celebration of the season.
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The Rankine scale is identical to the Fahrenheit, except that it avoids negative
numbers by initializing at absolute zero (-459.67 °F). You encounter it from
time to time in engineering literature. Its name honors William John Macquorn
Rankine (1820-1872), who also left us the following comments regarding those
newfangled metric units he strove to avoid:
Some talk of millimetres, and some of kilogrammes,
And some of decilitres, to measure beer and drams;
But I’m a British Workman, too old to go to school,
So by pounds I’ll eat, and by quarts I’ll drink, and I’ll work by my three-foot rule.
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John Dalton
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With the exception of the Dalton scale all of these are
linear. This means that given a known temperature scale reading of T1,
the unknown value for another scale, T2, equals (m * T1) + b
where m is called a slope and b a displacement. For Celsius to Fahrenheit, for
example, Fahrenheit = (1.8*Celsius) + 32. As in the cases of De Luc, Delisle,
Fowler, and the Royal Society of London that slope can be negative. That indicates
their numbers go down with increasing kinetic energy rather than up. The Celsius scale
originally worked this way, with 100 freezing and 0 boiling, until botanist Carl
Linnaeus switched it in 1744.
John Dalton’s system is logarithmic.
This is useful when you’re plotting temperatures that vary exponentially,
such as among different star types. Absolute zero is negative infinity in this
scale, freezing is 0.0 Daltons, water boils at 100, lead melts at around 253, and so
forth. Every hundred Daltons multiplies the thermodynamic energy by the ratio 373.15/273.15 or
approximately 1.37.
The converter below will translate between any pair of scales out of the 42. As a bonus it will display the formula
for a direct conversion between them, plus the values of any mathematical intersections.
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| Absolute zero | 0 K | -273.15 °C | -459.67 °F |
| Tungsten becomes superconducting | 0.011 K | -273.14 °C | -459.65 °F |
| Niobium becomes superconducting | 9.26 K | -263.89 °C | -443.00 °F |
| Pluto’s mean surface temperature | 44 K | -229.15 °C | -380.47 °F |
| Nitrogen liquifies | 77.36 K | -195.79 °C | -320.42 °F |
| Coldest recorded Earth temperature | 183.95 K | -89.20 °C | -128.56 °F |
| Carbon dioxide freezes (“dry ice”) | 194.65 K | -78.50 °C | -109.30 °F |
| Mercury freezes | 234.32 K | -38.83 °C | -37.89 °F |
| Ice and salt water bath | 252.05 K | -21.10 °C | -5.98 °F |
| Triethylborane (TEB) auto-ignites | 253.15 K | -20.00 °C | -4.00 °F |
| Hibernating arctic ground squirrel | 270.25 K | -2.90 °C | 26.78 °F |
| Water freezes | 273.15 K | 0.00 °C | 32.00 °F |
| Heavy water freezes | 276.97 K | 3.82 °C | 38.88 °F |
| Superheavy (tritiated) water freezes | 277.64 K | 4.49 °C | 40.08 °F |
| Ideal wine storage | 285.9 K | 12.75 °C | 54.95 °F |
| Earth’s mean surface temperature | 287.75 K | 14.60 °C | 58.28 °F |
| Room temperature (typical) | 295.5 K | 22.35 °C | 72.23 °F |
| White phosphorus auto-ignites | 307 K | 33.85 °C | 92.93 °F |
| Hottest recorded Earth temperature | 330.95 K | 57.80 °C | 136.0 °F |
| Water boils | 373.15 K | 100.0 °C | 212.0 °F |
| Heavy water boils | 374.55 K | 101.4 °C | 214.5 °F |
| Superheavy (tritiated) water boils | 374.66 K | 101.5 °C | 214.7 °F |
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| Sugar carmelizes (typical) | 441.5 K | 168.4 °C | 335.0 °F |
| Paper auto-ignites (typical) | 505.0 K | 231.9 °C | 449.3 °F |
| Lead melts | 600.6 K | 327.5 °C | 621.4 °F |
| Mercury boils | 629.9 K | 356.7 °C | 674.1 °F |
| Venus’s mean surface temperature | 735.0 K | 461.9 °C | 863.3 °F |
| Self-cleaning oven cycle (typical) | 775.0 K | 501.9 °C | 935.3 °F |
| Magnesium ribbon auto-ignites | 903.0 K | 629.9 °C | 1,166 °F |
| Table salt melts | 1,074 K | 800.9 °C | 1,474 °F |
| Gold melts | 1,337 K | 1,064 °C | 1,948 °F |
| Table salt boils | 1,686 K | 1,413 °C | 2,575 °F |
| Iron melts | 1,811 K | 1,538 °C | 2,800 °F |
| Lead boils | 2,022 K | 1,749 °C | 3,180 °F |
| Light bulb filament (typical) | 2,820 K | 2,547 °C | 4,616 °F |
| Gold boils | 3,129 K | 2,856 °C | 5,173 °F |
| Iron boils | 3,134 K | 2,861 °C | 5,182 °F |
| Oxyacetylene Torch | 3,350 K | 3,077 °C | 5,570 °F |
| Tungsten melts | 3,695 K | 3,422 °C | 6,191 °F |
| Diamond melts | 3,550 K | 3,277 °C | 5,930 °F |
| Diamond boils | 5,100 K | 4,827 °C | 8,720 °F |
| Earth’s center (inferred) | 5,700 K | 5,427 °C | 9,800 °F |
| Solar surface | 5,799 K | 5,526 °C | 9,979 °F |
| Tungsten boils | 5,828 K | 5,555 °C | 10,031 °F |
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Please note that the conversions between temperatures on this page are not guaranteed.
The definitions of some of these scales, especially the more obscure ones, fall far short of
modern standards for precision and reproducibility. If you spot any errors that you can correct,
or know of any other scales I might be able to include, feel free to contact me. Many
thanks.
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