The metre was originally defined in 1791 by the French National Assembly as one ten-millionth of the distance from the equator to the North Pole along a great circle through Paris, setting 10000 km as that quarter of the Earth’s polar circumference.
There was the navigation rationale for setting the meter/metre at the length that it is, but the original and subsequent definitions proved to be inconsistent and difficult to measure precisely.
There was the navigation rationale for setting the meter/metre at the length that it is, but the original and subsequent definitions proved to be inconsistent and difficult to measure precisely.
It’s also not accurate because one of the people who measured that distance made a small mistake in their calculations.