FRENCH GEODESIC MISSION: ANTECEDENTS, CONTRIBUTIONS AND PARTICIPANTS - HISTORY - 2025

The French geodetic mission was a scientific expedition carried out in the 18th century at the Royal Court of Quito, today the territory of Ecuador. The main objective was to measure the distance equivalent to one degree of latitude and to see what the real shape of the planet was.

Also known as the geodesic mission, the Spanish-French geodesic mission, its members left in May 1735 for Cartagena de Indias. From there, they covered a large part of the territory of the Royal Court, taking measurements.

La Condamine - Source: Louis Carrogis Carmontelle

In addition to achieving its main objectives, the mission also made a number of other important scientific contributions. Its results made it considered one of the first modern scientific expeditions with the participation of several countries.

The components of the mission were mainly French and Spanish. They were joined, already on the ground, by Pedro Vicente Maldonado, a native of the then Viceroyalty of Peru. In addition to helping to carry out the expedition's work, Maldonado made the first geographical map of Quito.

Background

The exact shape of the Earth was one of the most controversial issues among European scientists in the early 18th century. Followers of Newton's theories pointed out that it had a flattened shape at the poles, something that supporters of Cassini and Descartes did not accept.

The French Academy decided to end these discussions. To do this, he requested help from the King of France, Louis XV, and they proceeded to mount two expeditions that would settle the issue. The objective would be to measure the length of a degree of meridian in both arctic regions and the equatorial zone.

The expedition

Before leaving for Ecuador, the French asked Felipe V of Spain for permission to enter his, then, domains. The monarch gave his consent, on the condition that Spanish scientists participate.

Journey

The geodesic mission started in May 1735. Its first destination was Cartagena de Indias, to later follow the Guayaquil route and the Bodegas road.

At that time there were some discrepancies between the main members of the expedition, La Condamine, Godin and Bouguer. Finally, they decided to divide the mission into three groups.

The scientists reached Quito in June 1736, where they met Vicente Maldonado, who knew the area perfectly. With their help, the mission left the city and began triangulating measurements near Cuenca. These geodetic tasks lasted 3 years, until 1739.

In addition to taking measurements, members of the expedition climbed some of the mountains and volcanoes in the area. La Condamine started on her way back to Europe after having sailed down the Amazon River, reaching Cayenna.

For his part, Bouger preferred the land route that linked Quito to Cartagena to embark for Europe, while Godín remained in America for a while longer.

Second mission

Although less known, in 1901 a second mission arrived in Guayaquil. The organizer had been the Geographical Service of the French Army and its objective was to ratify or rectify the measurements made by the first mission.

Main contributions

The results of the geodetic mission in France represented a true scientific revolution in their time. Not only because of his confirmation that the Earth was flattened by the poles, but also because of other contributions resulting from his work in Ecuador.

Measuring the degree of the meridian and determining the shape of the Earth

Measuring the degree of the meridian was the main objective of the expedition. The ultimate purpose was to end the fighting over the real shape of the planet.

Once the measurements had been made, the results were compared with those obtained by another similar expedition that had been sent to Lapland.

Thanks to the work carried out, the debate was settled and it was established that the terrestrial poles have a slightly flattened shape.

Contribution for length measurements

La Condamine carried out a fundamental experiment to establish the meter as a standard measure of length. The scientist suggested that the base should be the distance traveled in one second by a pendulum in Ecuador.

Years later, in 1791, the Constituent Assembly of France used the measurements made by La Condamine (in addition to those made by Delambre between Dunkerque and Barcelona) to establish the value of a “meter”.

Contributions to various sciences

The mission also made contributions within geography, topography, physics, or anthropology. Among the most prominent are investigations of terrestrial and astronomical refraction, observations of the Moon and the satellites of Jupiter, the determination of the obliquity of the ecliptic, and the survey of various geographic charts.

Contributions for Ecuador

The presence, from the arrival in Quito, of Pedro Vicente Maldonado, made the mission also leave some scientific milestones for the Royal Audience.

Although the scientist already knew a good part of the territory, his work with the expedition allowed him to expand his knowledge. The result was the first map of the Presidency of Quito.

In addition, he was the author of another map of the course of the Amazon River, in addition to discovering the rubber and the qualities of quinine.

Participants

Although the French Academy was the organizer of the mission, Spanish scientists also participated in it. Among its members were astronomers and physicists, botanists and various engineers

Charles Marie de La Condamine

Charles-Marie de La Condamine was born in Paris in January 1701. He stood out for his work as a naturalist, mathematician and geographer, being one of the most respected scientists of his time.

La Condamine had several confrontations with other members of the mission, especially with the Spanish Jorge Juan and Antonio de Ulloa. His relationship with Louis Godin and Pierre Bouguer was not easy either, so they ended up returning to Europe each on their own.

Back in Paris, the scientist published the result of his findings. In addition to the central theme of the expedition, confirming that the Earth was flattened by the poles, La Condamine was the first to describe curare in Europe.

Other contributions of the scientist during the expedition were to take the rubber to Europe and point out the qualities of quinine to fight against malaria. He also established the basis for the decimal system.

Louis Godin

Louis Godin was a French astronomer and mathematician who came to assume for a short time the position of Chief Cosmographer of the Viceroyalty of Peru.

Along with La Condamine and Bouguer, he was one of the leaders of the French geodetic mission, as they were the three most respected scientists.

Pierre Bouguer

Also French, Pierre Bouguer was a French astronomer and mathematician. However, he has gone down in history as the father of naval architecture.

In 1749 he published La figure de la terre, determinée par les observations de Messieurs Bouguer, & de la Condamine, de l'Académie Royale des Sciences, envoyés par ordre du Roy au Pérou, pour observer aux environs de l'Équateur: avec une relation Abrégée de ce voyage, which contains the description of the countries in the region of the operations ont été faites.

With that long title, the book exposed all the scientific results of the French Geodesic Mission.

References

1. Fabara Garzón, Eduardo. The French Geodesic Mission. Obtained from elcomercio.com
2. Núñez Sánchez, Jorge. The First French Geodesic Mission. Obtained from eltelegrafo.com.ec
3. Aviles Pino, Efrén. French Geodesic Mission. Obtained from encyclopediadelecuador.com
4. Robinson, Andrew. History: How Earth shaped up. Retrieved from nature.com
5. Horrel, Mark. Chimborazo's role in proving Newton's theory of gravity. Retrieved from markhorrell.com
6. Pletcher, Kenneth. Charles-Marie de La Condamine. Retrieved from britannica.com
7. The Biography. Biography of Charles-Marie de la Condamine (1701-1774). Retrieved from thebiography.us