On 6/03/06 8:43 AM, "Han Maenen" <[EMAIL PROTECTED]> wrote:
I would personally prefer to call these units neo-Napoleonic or second
hand
metric units to-day. Napoleon is often wrongly credited with spreading
the
metric system over Europe, while in fact he almost brought it down. It
was
under Napoleon that for the first time old units were defined in terms of
metric ones, and the USA did that again in 1893.
I do not like the prefix 'metric' for USA and UK units.
Dear Han,
Thanks for the information on Napoleonic times and also for your opinion
about the use of terms such as the metric inch of exactly 25.4
millimetres.
It would appear that others (see below) have referred to this as the
'international inch'.
I have now had a chance to investigate this a little further and I found
this interesting quotation in Marvin H. Green's book, 'Metric Conversion
Handbook'.
The following is quoted from Barbrow and Judson:
'Since 1959 the yard is defined as being equal exactly to 0.9144 meter;
the
new value is shorter than the old value by two parts in a million. At the
same time it was decided that any data expressed in feet derived from
geodetic surveys within the U.S. would continue to bear the relationship
as
defined in 1893 (one foot equals 1200/3937 meter). This foot is called the
U.S. survey foot, while the foot defined in 1959 is called the
international
foot. Measurements expressed in survey miles, survey feet, rods, chains,
links, or the squares thereof, and also acres should therefore be
converted
to the corresponding metric values by using pre-1959 conversion factors
where more than five significant figure accuracy is involved.'
The Barbrow and Judson reference is to:
BARBROW, LOUIS E., AND JUDSON, LEWIS V. Units and Systems of Weights and
Measures; Their Origin, Development, and Present Status. National Bureau
of
Standards Letter Circular LC 1035. U.S. Department of Commerce. Prepared
by:
Lewis V. Judson, Office of Weights and Measures, National Bureau of
Standards, January 1960. Revised by: Louis E. Barbrow, Office of Metric
Information, National Bureau of Standards, June 1975.
Marvin Green then goes on to add:
'Therefore, this book (Metric Conversion Handbook) includes the survey
mile,
survey foot, rod, chain, and link as units based on the 1893 definition of
the foot. In addition, the international foot and mile are included but
without the adjective. From the quoted statements it appears that the yard
is not related to geodetic surveys'.
There is a wonderful maxim in English that goes: 'Oh, what a wicked web we
weave, when first we practise to deceive'.
I will probably continue to use the expressions 'metric inch' (of exactly
25.4 mm), 'metric foot' (of exactly 304.8 mm) and 'metric yard' (of
exactly
914.4 mm) because in doing so it challenges anti-metric folk to think
about,
and hopefully question, the fundamentally unsound basis of all the old
measures that they support. On this matter, I think that you and I will
continue to disagree.
Cheers,
Pat Naughtin
PO Box 305, Belmont, Geelong, Australia
Phone 61 3 5241 2008
