Charles Marie de La Condamine (1701-1774)
Autograph letter signed (‘La Condamine’) to [Jean-Jacques d'Ortous de Mairan], Cayenne, 10 August 1744
In French. Four pages, 225 x 176mm, bifolium, with a pencil inscription by the recipient. Provenance: Sotheby’s, 16 May 1978, lot 358.

The French geographer La Condamine reports from South America on his experiences in Cayenne, Pará and Quito, as well as his experiments measuring degrees of latitude at the equator. La Condamine awaits the King’s ship, hoping that this will bring him to Martinique and then to France on the September current. He consoles himself in the meantime with the thought that the same ship may bring letters from France; he has not received a single one for four years. In his last dispatch, he included a sealed packet for the French ambassador to Portugal, containing papers to be submitted to the Academy in case his ship to Europe should wreck. He reports on measurements taken with a pendulum at Quito and Pará, with his altitude for each measurement. He encloses a copy of a letter which he sent to the Count de Maurepas, as well as letters for his mother and sisters [not present]. He discusses the theory [of Isaac Newton] that the earth bulges around the equator, although he has not been able to get hold of the most up-to-date journals.

Charles Marie de La Condamine spent ten years in South America taking measurements around the equator and mapping the Amazon. He travelled there as part of the French Geodesic Mission to test Newton’s theory. He left Cayenne the month that this letter was written and arrived in Amsterdam on 30 November. His recipient, Jean-Jacques d'Ortous de Mairan (1678-1771) was a polymathic natural philosopher who made contributions to the fields of astronomy and biology among others. See lot 346 for a financial document relating to the expedition signed by La Condamine, and lot 353 for letters about it by d'Ortous de Mairan.