for old europe :
Quote:Fahrenheit is a temperature scale named after the German physicist Daniel Gabriel Fahrenheit (1686-1736), who proposed it in 1724.
In this scale, the freezing point of water is 32 degrees Fahrenheit (written "32 °F"), and the boiling point is 212 degrees, placing the boiling and freezing points of water exactly 180 degrees apart. On the Celsius scale, the freezing and boiling points of water are exactly 100 degrees apart, thus the unit of this scale, a degree Fahrenheit, is 5⁄9 of a degree Celsius. Negative 40 degrees Fahrenheit (-40 °F) is equal to negative 40 degrees Celsius (-40 °C).
Celsius to Fahrenheit : °F = (°C ?- 1.8) + 32
example : 20 C x 1.8 + 32 = 68 F ... simple , isn't it ?
i recall that thermometers in germany often had the celsius scale on one side and the reaumur scale on the other .
our physics teacher insisted that we be able to switch between those three scales easily .
Quote:The Réaumur scale is a temperature scale named after René Antoine Ferchault de Réaumur, who first proposed it in 1731. The freezing point of water is 0 degrees Réaumur, the boiling point 80 degrees Réaumur. Hence, a Reaumur degree is 1.25 Celsius degrees or kelvins. The Réaumur temperature scale is also known as the octogesimal division (division octogesimale in French).
Réaumur's thermometer was constructed on the principle of taking the freezing point of water as 0°, and graduating the tube into degrees each of which was one-thousandth of the volume contained by the bulb and tube up to the zero mark. It was the dilatability of the particular quality of alcohol employed which made the boiling point of water 80°. Mercurial thermometers, the stems of which are graduated into eighty equal parts between the freezing and boiling points of water, are not Réaumur thermometers in anything but name. Réaumur may have chosen the octogesimal division because the number 80 could be halved 4 times and still be an integer (40, 20, 10, 5); the number 100, for instance, could only suffer this process 2 times (50, 25).
The Réaumur scale saw widespread use in Europe, particularly in France and Germany (as well as Russia - as in works of Dostoyevsky), but was eventually replaced by the Celsius scale
anyone want to switch between those three scales :wink:
hbg
