Journal du Voyage fait par Ordre du Roi a l'Equateur, servant d'Introduction Historique a la Mesure des Trois Premiers Degres du Meridian

4to [25 x 20 cm]; [ii], xxxvi, 280, xv (index) pp, 7 engraved maps, plans and plates including 6 folding, one being fldg table, engraved vignette head-pieces and tail-pieces. contemporary full leather, gilt spine title & design, raised bands, light cover wear, few tiny holes on front joint,marbled endpapers, endpaper labels of Le Chev du Blaisel & B. Mendel, few leaves with light marginal browning, else clean crisp, near fine. This is the first edition of the account of the great French Scientific Expedition to South America to measure an arc of the meridian at the equator to determine the dimension and shape of the earth. After the scientific measurements done north of the city of Quito in Ecuador, La Condamine then journeyed down the Amazon, being the first to explore that region. His measurements stood the test of time until the advent of GPS showed that the actual equator was somewhat further south, although the original monument and museums north of Quito still advertise themselves as the actual equator. The work includes a detailed plan of the city of Quito and a large map of what is now Ecuador. Hill 169: 'the greatest geographical event of the eighteenth century as regards South America. . . to measure one exact degree of meridian to determine the dimensions and shape of the earth. . . the work occupied eight years'. Sabin 38479. Norman 1250.