"What standard distance was selected because it was expected to be ""one ten millionth of the quadrant of the earth's meridian"""
History of the metre for the meridional definition of the metre. While the Ordnance Survey extended the British survey northward to the Shetland, Arago and Biot extended the survey southward in Spain to the island of Formentera in the western Mediterranean Sea (1806–1809), and found that one ten-millionth of the Earth's quadrant should be 443.31 ': later work increased the value to 443.39 "". This new survey of the Paris meridian arc, named West Europe-Africa Meridian-arc by Alexander Ross Clarke, was undertaken under the direction of François Perrier from 1870 to his death in 1888. Jean-Antonin-Léon Bassot completed the task in 1894. The modern
History of the metre of 10 hours to the day, 100 minutes to the hour and 100 seconds to the minute - introduced in 1793. Instead of the seconds pendulum method, the commission – whose members included Lagrange, Laplace, Monge and Condorcet – decided that the new measure should be equal to one ten-millionth of the distance from the North Pole to the Equator (the quadrant of the Earth's circumference), measured along the meridian passing through Paris. Apart from the obvious consideration of safe access for French surveyors, the Paris meridian was also a sound choice for scientific reasons: a portion of the quadrant