French Geodesic Mission to Lapland
The French Geodesic Mission to Lapland was one of the two geodesic missions carried out in 1736–1737 by the French Academy of Sciences for measuring the shape of the Earth. One expedition was sent to Ecuador to perform measurements near the Equator; the other was sent to Torne Valley to perform measurements near the Arctic Circle.
Source: Wikipedia — French Geodesic Mission to Lapland (CC BY-SA 4.0)