They do not cite their reasoning. They simply say they picked it, equivalent to my statement, "because." PS: Can you cite a reference for the centigrade being 1/100 of a right angle. Rowlett's Units of Measure show the grad and grade as alternative names and themselves 1/100 of a right angle. A centigrad would be a ten-thousandth. http://www.unc.edu/~rowlett/units/dictG.html I am not advocating a return to degree centigrade; I am just saying in my mind it is no big deal. Everyone knows what is meant and it does not lead to a symbol error. --- On Mon, 12/14/09, Martin Vlietstra <[email protected]> wrote:
From: Martin Vlietstra <[email protected]> Subject: [USMA:46285] Re: Celsius To: "U.S. Metric Association" <[email protected]> Date: Monday, December 14, 2009, 4:15 PM Apparently in 1948 the CIPM and the CGPM thought so. See http://www.bipm.org/en/committees/cipm/cipm-1948.html (SI – Brochure) From: [email protected] [mailto:[email protected]] On Behalf Of John M. Steele Sent: 14 December 2009 20:58 To: U.S. Metric Association Subject: [USMA:46284] Re: Celsius That should not be an overriding consideration. The grade is not a Table 8 unit (Non-SI unit accepted for use with the SI) like the degree. It is a national unit, little used elsewhere and confused easily with the grad for which 100 grad is a quadrant and 400 grad, a circle, at least according to my calculator (the grad is ALSO little used). In any case temperature is disambiguated by use of the term "degree Centigrade" and symbol °C. Degree Celcius replaced it because the CIPM and CGPM said so. --- On Mon, 12/14/09, Martin Vlietstra < [email protected] > wrote: From: Martin Vlietstra < [email protected] > Subject: [USMA:46283] Re: Celsius To: "U.S. Metric Association" <[email protected]> Date: Monday, December 14, 2009, 3:32 PM The reason that degrees celsius replaced degrees centigrade is that in French one centigrade is one hundredth of a right angle. From: [email protected] [mailto:[email protected]] On Behalf Of John M. Steele Sent: 14 December 2009 17:02 To: U.S. Metric Association Subject: [USMA:46282] Re: Celsius Yes, it is still pretty common. I'm pragmatic and I don't worry about it much. I'd much rather they measure in degrees Centigrade than in Fahrenheit. I think the symbols are more important than the words.I am more concerned by improper uses that are likely to carry over into improper symbolization. As examples, I would offer: *The use of the micron for micrometer. This is likely to carry over into the use of a standalone prefix. *Mostly gone now, but when pico- was first introduced, small value capacitances continued to be referred to as micromicrofarads, rather than picofarads for many years. I consider those more worthy of correction, but rarely even bother to correct Centigrade. --- On Mon, 12/14/09, Paul Trusten < [email protected] > wrote: From: Paul Trusten < [email protected] > Subject: [USMA:46279] Celsius To: "U.S. Metric Association" <[email protected]> Date: Monday, December 14, 2009, 10:51 AM Celsius has been the official name for a commonly used SI-derived temperature scale for 60 years. Yet, there seems to be some kind of tacit agreement among people to continue to call it centigrade. I was actually pleasantly surprised to hear a Discovery Channel voice call it Celsius for once. People in my department call it centigrade no matter how frequently I gently remind them. Do you have this problem? Does this happen outside the U.S. ? Paul Trusten
