French Geodesic Mission
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The French Geodesic Mission (also called the First Geodesic Mission and the Spanish-French Geodesic Mission) was an 18th-century expedition to Ecuador carried out for the purpose of measuring the roundness of the Earth and measuring the length of a degree of longitude at the Equator. The mission was one of the first geodesic (or geodetic) missions carried out under modern scientific principles.
[edit] Background
In the 18th century, there was significant debate in the scientific community, specifically in the French Academy of Sciences (Académie des sciences), as to whether the circumference of the Earth was greater around the Equator or around the poles. French astronomer Jacques Cassini held to the view that the polar circumference was greater. The Louis XV, the King of France and the Academy sent two expeditions to determine the answer: one was sent to Lapland, close to the North Pole, under Swedish physicist Anders Celsius and French mathematician Pierre Maupertuis. The other mission was sent to Ecuador, at the Equator. Previous accurate measurements had been taken in Paris by Cassini and others.
[edit] Expedition
The equatorial mission was led by French geographers Charles Marie de La Condamine, Pierre Bouguer, Louis Godin and Spanish geographers Jorge Juan and Antonio de Ulloa. They were joined in Ecuador by Ecuadoran geographer and topographer Pedro Maldonado. (Maldonado later traveled to Europe to continue his scientific work.)
- Note: In the 18th century the nation of Ecuador did not yet exist. The area was under Spanish control and was called the Territory of Quito after the city of Quito. The fame brought to the region by the French Geodesic Mission appears to have influenced the adoption of the name, Republic of Ecuador when the country gained independence in 1830.
The Ecuadoran expedition left France in May 1735. They landed on the Caribbean coast in Colombia and traveled overland to Panama, then sailed to Ecuador. In Ecuador they were met by Maldonado, traveled through rainforests, sailed up the Esmeraldas River, and then climbed up the Andes Mountains. They arrived in Quito, Ecuador, on June 4, 1736.
La Condamine and his colleagues measured arcs of the Earth’s curvature on the Equator near Quito and near Pedernales on the Pacific Coast. These measurements enabled the first accurate determination of the size of the Earth and led to the establishment of the international metric system of measurement.
They completed their measurements by 1739, measuring the length of an arc of one degree at the Equator. Soon afterwards the scientists received the news that the Lapland expedition had already finished their work and had proven that the Earth is oblate, i.e., flattened at the poles.
La Condamine remained in South America for four more years, doing scientific work and mapping some of the Andes and much of the Amazon River. He returned to France by climbing the Andes Mountains and rafting down the Amazon River. He arrived in Paris in 1745, 10 years after he left France.
[edit] Observations during the mission
- Ulloa and Juan visited the architectural Inca complex in San Agustin de Callo and subsequently wrote a descriptive document of what they observed at the ruins. Ulloa made a drawing of the ruins.[1]
[edit] Subsequent Mission
In the late 19th century, the Academy of Sciences sent another mission to Ecuador to confirm the results of the First Geodesic Mission. This second mission was led by General Charles Perrier.
[edit] Publications
Bouguer published the results of the expedition in 1749, in his work Figure de la terre determine.
[edit] Monument
In 1936, the French American Committee of Ecuador sponsored the idea of the Ecuadoran geographer Dr. Luis Tufiño and raised a monument commemorating the bicentennial of the arrival of the First Geodesic Mission. They raised a 10-meter-high monument at Mitad del Mundo in San Antonio de Pichincha, in Pichincha Province of Ecuador. However, there is no record that the Mission ever visited the area.
