A planetary question
In the eighteenth century, scientists still debated the precise shape of Earth. The French Geodesic Mission to the Equator, conducted from 1735 to 1739 in what is now Ecuador, set out to measure the length of a degree of latitude at the Equator and determine Earth’s roundness.
“Geodesy” is the science of measuring Earth’s shape and size. The expedition applied modern scientific principles to a problem that required observations across rugged terrain, careful surveying, and international cooperation.
An international expedition
French astronomers Charles Marie de La Condamine, Pierre Bouguer, and Louis Godin worked alongside Spanish geographers Jorge Juan y Santacilla and Antonio de Ulloa. Joseph de Jussieu and Jean Godin assisted, while Ecuadoran geographer and topographer Pedro Maldonado contributed local expertise.
The mission involved a network of ships moving between Spain, Colombia, Ecuador, Chile, and France. Its scientific reports transformed measurements taken far from Europe into published knowledge shared across borders.
More than a measurement
The expedition represented a new model of exploration. Naval movement, astronomy, geography, and mathematics combined to answer a question about the entire planet. It was among the first major international scientific expeditions conducted according to modern standards.
Its significance reached beyond the final numbers. The mission demonstrated that global questions required cooperation among specialists from different countries and regions. It also showed how exploration could turn remote landscapes into sites of precision science.
The striking lesson is that one of the earliest modern international scientific projects began not with a laboratory, but with surveyors crossing the Equator.