In the 1730s the French Académie des Sciences was planning a scientific expedition to South America under the leadership of the geographer, astronomer, and mathematician Charles-Marie de La Condamine (1701-74). Its goal was to measure the exact length of a degree of longitude at the equator in Peru, thus enabling an accurate measurement of the circumference of the earth. A similar expedition was planned north to Lapland under Pierre Louis de Maupertuis to measure the earth’s circumference through the poles. This was to discover the exact shape of the planet; whether it was round or flattened at the poles as suggested by Isaac Newton and others.

As Peru was a Spanish possession, permission was sought from the authorities. Philip V of Spain granted permission provided two Spanish officers accompanied them. These were Jorge Juan (1713-73) and Antonio de Ulloa (1716-95). The two parties met at Cartegena in November 1735. The Spaniards remained with La Condamine until 1740 when they were called to Lima because of the impending threat of George Anson’s voyage. After a long wait the two made it to the Juan Fernandez Islands where they undertook a survey. In February 1743 they made there way to Concepcion, Valparaiso, Callao, and Quito.

The two left Callao in October 1744 for the return voyage to Europe on separate French vessels. Whilst Ulloa made it back safely, Juan’s voyage was beset with difficulties. Whilst traversing the Sargasso Sea it was boarded by English privateers who took them to Louisbourg on Cape Breton Island. The siege of Louisbourg occurred that year and it fell to British control, the Spanish were declared prisoners of war and shipped to London. With Ulloa’s scientific capabilities he was shortly made a member of the Royal Society and with the help of its president released to return to Spain arriving in Madrid in July 1746. For the next two years, the two of them worked on preparing this account of the voyage.

This is the first edition of the work, translations followed in various formats, but this is the rarer and best account. Amongst the scientific work the voyage also recounts one of earliest descriptions of the Aurora Australis. The end of the fourth volume includes a Historical Summary of the Origin and Succession of the Incas and Other Sovereigns of Peru with separate pagination.

The work includes several very fine plans of the cities of Cartegena, Quito, Lima, amongst other plans of harbours. The detailed geodetic work is displayed on a joined two sheet map. The result of their work on Juan Fernandez Island is also included, the island made famous by Alexander Selkirk and the inspiration for ‘Robinson Crusoe’. Finally, there is a large folding chart of the entire west coast of South America. Provenance: Libraria de Antanao 1998; Juan and Peggy Rada Collection. Brunet (1860-80) V1006; Hill 1739; Howgego (2003) L9 & U3; Kapp (1971) nos. 83 & 84; Medina (1897) BHA, 3464; Palau (1948-77) 125471; Sabin (1868-1936) 36811; Shirley (2004) G.Ull 1a.