Geographical mile longitude at the equator is thus exactly 60 geographical miles. It was closely related to the nautical mile, which was originally determined as 1 minute of arc along a great circle of the Earth, but is nowadays defined as exactly 1852 metres. The US National Institute of Standards and Technology (NIST) notes that: "The international nautical mile of 1 852 meters (6 076.115 49...feet) was adopted effective July 1, 1954, for use in the United States. The value formerly used in the United States was 6 080.20 feet = 1 nautical (geographical or sea) mile." (6080.2 feet is 1853.24496 meters.)
Obsolete Austrian units of measurement the traditional Roman foot remained in common use in Prague. When the metric system was introduced by law on 23 July 1871 (which became obligatory on 1 January 1876), the length of the "klafter" (kl) was established as exactly 1.89648384 metres. Austrian post-mile, police-mile, geographic mile = 3,910 Viennese "klafters". Obsolete Austrian units of measurement Austrian units of measurement were used in Austria until the adoption of the metric system. In 1756, the ruling Arch duchess of Austria, Maria Theresa, ordered that the Viennese "klafter" as well as its multiples and fractions, should be the state-defined measure of length in