Geodetic expedition to Lapland (Earth's flattening)
Expedición geodésica a Laponia (achatamiento terrestre)
- Date
- 1736-1737 · confidence high
- Place
- Tornio, Lapland, Finland
- Credited to
- Pierre Louis Maupertuis, Alexis Clairaut, Anders Celsius and Pierre Charles Le Monnier
- Field
- Cosmos & Earth
What was discovered
Measurement of a meridian arc along the Tornio river that gave a longer degree near the pole than in France, confirming that the Earth is flattened at the poles. It vindicated Newton against the Cartesian hypothesis of an elongated Earth.
The Lapland measurement was repeated in 1801 and a considerable error found, so its numerical value is wrong although the conclusion was right. Its result came before that of the Equator expedition.
What it led to
- the Earth's shape as an oblate spheroid
- set the model for Clairaut's theory of the figure of the Earth