- Geographical mile
unit of length
m= 1855.325
accuracy=4The geographical mile is a unit of length determined by 1 minute of arc along theEarth 'sequator , approximately equal to 1855.325metre s (6087.025 international feet). Any greater precision depends more on choice of standard than on more careful measurement: the length of theequator in theWorld Geodetic System WGS-84 is 40,075,016.6856 m which makes the geographical mile 1855.3248 m, while theInternational Astronomical Union standard IAU-2000 takes theequator to be 40,075,035.5351 m making the geographical mile 1855.3257 m, almost a millimetre longer.The unit is not used much; it is closely related to the
nautical mile , which was originally determined as 1 minute of arc along agreat circle of the Earth but is nowadays anSI standard length defined as exactly 1852 metres.The Danish and German geographical mile ("mil" and "Meile" respectively) is 4 minutes of arc, and was defined as approximately 7421.5 metres by the astronomer
Ole Rømer ofDenmark . InNorway andSweden , this 4 minute geographical mile was mainly used at sea ("sjømil"), up to the beginning of the 20th century.ee also
*
conversion of units
*Medieval weights and measures for details of the geographicalleague ofFrance
*mile for the various other miles in use
*nautical mile
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