[editor-surveyor]

"On April 5, 1893 the inch was redefined as precisely 1/39.37 meter, and in a very real sense we have been using the metric system ever since. In 1959 the length of the inch was shortened slightly to its present definition of 2.540 000 000 centimeters."

You're mixing up apples and oranges and getting rotten fruit salad ;o)

In 1959 a new unit was created, called the "international foot." That foot was the only one that uses an inch that is defined relative to the meter. The real foot, which is called the "U.S. Survey Foot" is still defined based on a physical standard unit that is stored at the NIST. That unit cannot be changed for serious legal reasons, and it is the only "foot" that can legally used for measurement. (Nobody really knows what the "international foot" is good for)

[cynwoody]

(Nobody really knows what the "international foot" is good for)

Easier calculation, I suppose. A US survey mile is about an eighth of an inch longer than an international mile.