On 2007 Nov 29 , at 3:37 PM, James Frysinger wrote:
From Tenn Code Annotated:
66-6-103. Technical definitions of systems. —
(c) The definition of the “U.S. Survey Foot,” with the associated
factor of 1 m = 39.37/12 feet, shall be used in any conversion
necessitated by changing values associated with the Tennessee
Coordinate System of 1983, from meters to feet.
This definition (above) of the "survey foot" is not the same as the
definition based on the "official" definition of the inch as EXACTLY
25.4 mm.
From this official and legal definition, a metre is:
1 m = 1000/(25.4 x 12) feet EXACTLY
or
1 m = 1/0.3048 feet EXACTLY
or
1 m = 3.280 839 895... ft. APPROXIMATELY
where the dots (...) indicate an infinitely long repeating decimal
where the repetition begins way out past the 40th decimal point
somewhere. (Yes, I calculated it!)
The Tennessee definition of the metre,
1 m = 39.37/12 ft., is EXACT but gives:
1 m = 3.280 833 333... ft. APPROXIMATELY
where the dots once again indicate an infinitely long repeating
decimal (in this case, all 3's).
The two approximate decimal forms are not equal, so the two
definitions of the foot are not the same. (The discrepancy begins in
the sixth decimal place.)
Am I confused by "survey foot" as opposed to an honest-to-goodness
good old American foot? Why would Tennessee want to define a foot
differently than the US Congress did when they chose an inch to be
25.4 mm?
