France Measured The Meter Wrong

When France first defined the meter, it set the length as one ten-millionth of the distance from the North Pole to the equator. French astronomers Jean Baptiste Joseph Delambre and Pierre Méchain were sent to measure the meridian arc needed for the calculation. But an error in the survey went unnoticed for decades, and the resulting meter ended up about 0.2 millimeters too short.

Previous Fact Next Fact