Duncan Bath wrote:
>
> -----Original Message-----
> From: Pat Naughtin <[EMAIL PROTECTED]>
....
> >Is a micron a nickname for micronewtons, mirolitres, micrometres, or
> >micrograms?
>
> Good question. It answers mine!
> On second thought - does it? The micron was specific to length, was it
> not?.
Yes, in 1948 the 9th CGPM declared, in Resolution 7, the micron's
symbol to be the lowercase Greek letter mu, but the micron existed
before then as a unit of length (not of mass, volume, or any other
quantity). I do not find in the brochure a note on when the micron was
first defined. The table accompanying the 1866 Act of Congress in the
U.S. does not include the micron (the length table ranges from
myriameter* down to millimeter) so that probably puts an early bound on
its inception. My Webster's Ninth New Collegiate Dictionary gives 1892
as the date it was first used and interestingly it was one year later
that the Mendenhall Order was published.
Jim
* myriameter = 10 km = 10 000 m; myria was an old metric prefix for 10
000.
--
Metric Methods(SM) "Don't be late to metricate!"
James R. Frysinger, CAMS http://www.metricmethods.com/
10 Captiva Row e-mail: [EMAIL PROTECTED]
Charleston, SC 29407 phone/FAX: 843.225.6789
