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
Mexican units of measurement Mexican units of measurement A number of units of measurement were used in Mexico to measure length, mass, area, capacity, etc. The Metric system was optional from 1857, and has been compulsory since 1896. The Units of the system (from Spanish, Castillian) were legally defined during the transition period of the metric system. A number of units were used. One vara (lit. "pole") was equal to 0.838m (32.99 inches) as it was legally defined also use inches and feet. Some other units and legal equivalents are given below: 1 linea (lit. "line") = 1/432 vara 1 pulgada (lit. "thumbful", "inch")