one ten-millionth of the shortest distance from the North Pole to the equator passing through Paris.
The stick of metal in Paris is just so people don’t have to do measure the distance between the north pole and the equator each time they want to check their measuring tool.
It was defined as
The stick of metal in Paris is just so people don’t have to do measure the distance between the north pole and the equator each time they want to check their measuring tool.