USGS has used meters since the early 1800s. They simply multiply by 3937/1200
or 1250/381 to give Survey or International feet according to each State's
preference as documented in their surveying laws and State Plane Coordinate
System. A few States just use meters. 50 States = 50 Ways (more or less,
sometimes, its hard to come up with 50 unique choices).
The Congress picked some non-ideal conversion constants in the Metric Act of
1866 and the 1893 Mendenhall Order simply used them to define Customary, the
foot being 1200/3937 m from 1893 to 1959, when it was renamed the Survey foot.
It you want to express the foot exactly as a fraction of a meter, you have use
that form, otherwise you get a repeating decimal, whereas the International
foot is defined in only 4 decimal digits.
Congress made a poor choice. Bronze Yard #11 (the former US standard measured
considerably closer to the modern value, 0.9144 m, than the value in the Metric
Act of 1866 and Mendenhall Order, 3600/3937, as documented in NIST SP 447.
Short live the Survey foot. (Most people don't even know it exists)
On Saturday, October 26, 2019, 6:41:11 PM EDT, Peter Goodyear
<[email protected]> wrote:
Hi, everybody,
NIST has announced that they will retire the US Survey Foot in two years time
as part of an upgrade to the National Spatial Reference System which will
relocate several landmarks in terms of latitude, longitude and altitude.
There is an article about this in a blog on the Scientific American website,
and an announcement by the National Institute of Science and Technology. Also,
interested parties are invited to comment by NIST. The article doesn’t say that
the reference system is going to switch to the metric system, so there is still
more work to be done in this area.
The Scientific American article has a headline saying "Farewell to the
Fractional Foot” I’ve never seen the US Survey Foot described this way before.
Has anyone else?
This has also been posted to Reddit’s Metric forum here:
https://nam01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fwww.reddit.com%2Fr%2FMetric%2Fcomments%2Fdnklrb%2Ffarewell_to_the_fractional_foot_scientific%2F&data=02%7C01%7Cusma%40lists.colostate.edu%7Cbc320a08aa2644d0e65508d75a6db994%7Cafb58802ff7a4bb1ab21367ff2ecfc8b%7C0%7C0%7C637077299638857737&sdata=efBX6CAmYNHmXXHhRqwkWjRwfuHWTCsj9sUTjjUh4Pg%3D&reserved=0
Best wishes,
Peter Goodyear,
Melbourne, Australia
e-mail: [email protected]
_______________________________________________
USMA mailing list
[email protected]
https://lists.colostate.edu/cgi-bin/mailman/listinfo/usma
_______________________________________________
USMA mailing list
[email protected]
https://lists.colostate.edu/cgi-bin/mailman/listinfo/usma
