Charles Marie de La Condamine

Charles Marie de La Condamine (1701–1774) was a French mathematician, geographer, and explorer who helped measure a meridian arc near the equator in present-day Ecuador.

French Geodesic Mission to the Equator: An eighteenth-century French expedition that measured a meridian arc near Quito to determine Earth’s shape. La Condamine joined this mission, whose measurements established the central episode of his career.
Meridian arc: A measured segment of a meridian used to estimate Earth’s size and shape. The mission compared the length of an equatorial arc with measurements at higher latitudes.
Isaac Newton: An English mathematician and physicist whose laws of motion and gravity transformed natural philosophy. Newton predicted that rotation would make Earth wider at the equator, prompting a decisive measurement.
Amazon River: A major South American river system draining the Andes and much of the continent into the Atlantic Ocean. La Condamine’s journey down the river produced an influential European account of its course.
Quito: The capital of Ecuador, situated high in the Andes near the equator. The expedition used Quito as its principal base for surveying the surrounding Andes.
Geodesy: The science of measuring Earth’s geometric shape, orientation, and gravitational field. La Condamine’s expedition applied geodetic methods to Earth’s figure.
Cassini family: A family of astronomers and cartographers associated with French measurements that suggested Earth was elongated at the poles. Their measurements conflicted with Newton’s prediction and sharpened the question La Condamine’s mission addressed.
Quinine: An antimalarial alkaloid found in cinchona bark, used to treat malaria. La Condamine described cinchona and helped publicize its medicinal use in Europe.
Pedro Vicente Maldonado: An Ecuadorian scientist and cartographer who assisted the French geodesic mission. Maldonado guided La Condamine through the region and collaborated on mapping and surveying.
Earth's shape: The form of Earth, approximated by an oblate spheroid but locally irregular. The arc survey helped assess whether Earth bulged at the equator or at the poles.

Linked from 2 pages