For everyday use, the celsius scale certainly has an intuitive factor going for it. For example, I would not relish weather maps with the isothermal line separating ice and snow from water and rain labelled 273.15 K
D. -----Original Message----- From: Ezra Steinberg <[EMAIL PROTECTED]> To: U.S. Metric Association <[EMAIL PROTECTED]> Date: March 5, 2002 19:38 Subject: [USMA:18553] Re: Centigrade-Celsius Differences >Given what Gene wrote, it looks to me like the use of the Celsius scale is >quite similar to the use of the liter, in that both are defined in terms of an >SI unit, are not themselves units, and are kept mostly for reasons of history >and convenience than anything else. > >Ezra > > >Gene Mechtly wrote: > >> What is the difference between the historical definition >> of the centigrade temperature scale and the modern Celsius scale? >> >> In 1742, Anders Celsius published a paper titled (after translation) >> "Observations on Two Constant Degrees on One Thermometer" in the >> Transactions of the Swedish Academy of Sciences. >> >> The *two constants* were the ice point and the boiling point of water, >> separated by exactly 100 degrees on that "centigrade" scale. Celsius >> chose the boiling point as the zero on his original scale. >> >> On the other hand, the modern Celsius scale has *only one* fixed point, >> a zero at 273.15 K, and an increment (unit) of temperature difference >> identical to 1 K, as Jim Frysinger has explained. >> >> Thus, the original "centigrade" scale was, in fact, *different* from the >> modern Celsius scale. >> >> However, the definition of the original centigrade scale, and its >> immediate successor with the zero reset at the ice point, were effectively >> discarded by a series of resolutions by the CGPM as Joe has explained. >> >> Gene. >
