Mail Archives: opendos/2001/04/08/08:26:24
"The unit of volume, the liter, was originally defined as 1 cubic
decimeter (cdm3), but in 1901 it was redefined as the volume occupied by
a kilogram of water at 4° C at 760 mm of mercury; in 1964 the original
definition (cdm3) was restored."
Extract from article titled "The Metric System."
[Microsoft® Encarta® Encyclopedia 2001.
© 1993-2000 Microsoft Corporation. All rights reserved.]
My [UK publication] SI Standards reference volume [published before MS
was founded!] details the 1964 change of basis in almost the same words,
but I had not seen the specifics of the 1899/1901 definitional change
until I looked in Encarta. [And I bet that if we checked, we'd find
that the 1899 GCWM findings were published in 1901...?]
Alan S.
4-8-2001
"Arkady V.Belousov" wrote:
> Not very so. In 1889 on the I General conference was affirmed the 1
> kilogramm as weight of 1 litre (1 dm^3) clear water at temperature of
> its most density. First weight etalon was implemented as platinum
> cylinder block at height and diameter of 39 cm. But later was find
> out that prototype was implemented not too precise and litre become
> not equal to 1 dm^3 (but with 0,0028% error). This was corrected on
> the XII General conference in 1964.
as173 AT cornell DOT edu (Alan S.) wrote:
> However, IIRC, there are two very slightly different 'inches', viz:
> The 'Historical' Imperial Inch equal to 2.539998... cm
> and the SI Inch which is an (SI) Special Name for [exactly] 2.54 cm
> [ For that matter, the litre was resized from 1,000.028 cubic cm to
> be a Special Name for (exactly) 1,000 cubic cm in 1964. ]
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