The founding of the Académie ------------------------------
In the 17th century, Louis XIV appoints Jean-Baptiste Colbert (1619–1683) as a minister, tasking him with restoring order to the finances of a country impoverished by wars with Spain. To this end, Colbert decides to take stock of the kingdom's resources. Among other information, he asks the provinces to provide maps, which are compiled by the cartographer Nicolas Sanson (1600–1667). The result confirms that the available geographical data are highly approximate. In an attempt to fill these gaps and resolve many scientific questions of the utmost importance, he founds the Académie royale des sciences. The new academicians then propose creating the Paris Observatory, whose main building, designed by Claude Perrault (1613–1688), is completed in 1672.
An abbot's enthusiasm ----------------------
The Jesuit abbot and astronomer Jean-Félix Picard (1620–1682) is commissioned to produce a new map of France. In Holland, cartographers draw up maps using scientific methods: they employ a technique pioneered by Willebrord Snell (1580–1626), known as triangulation. It involves measuring the distance between two points on level ground using measuring rods or surveyors' chains. From these two endpoints, the angles to a third landmark are measured. Trigonometry then determines the triangle exactly. All that remains is to add successive survey points to form new triangles—hence the term triangulation.
The newly founded Académie royale des sciences and Abbot Picard enthusiastically rise to the challenge. Picard builds the most precise instruments of the day: his quadrant has a resolution of one arcminute. It is used to measure a section of the meridian from Malvoisine (near Montlhéry in Essonne, 30 km south of Paris) to Sourdon (in the Somme, 20 km south of Amiens).