Earth's circumference mile in the seventeenth century and the metre in the eighteenth. Earth's polar circumference is almost exactly 40,000 km because the metre was originally calibrated on this measurement (1/10-millionth of the distance between the poles and the equator), which is almost exactly 21,600 nautical miles (being defined as one minute of a degree – i.e. 360 multiplied by 60). It has been described as "the single most important measurement" of the Earth, assuming the Earth to be a sphere (the Earth is an technically an ellipsoid, albeit with just 0.3% flattening). Earth's circumference lines are the foundation of the coordinate
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