Cassini

The first geometrical map of the Kingdom of France was realised, at a scale of 1:864,000, on the initiative of Louis XV. It is known as the Cassini Map. The Cassini family produced four generations of scholars. The first Cassini, an astronomer, began to apply a geodesic system that consisted of measuring the position of a point on Earth using bearings, namely the polar axis and the Equator. His descendants established a precise map of France (180 sheets) by triangulating a large number of bearings, such as Pic Cassini. It was used as a model for France's Ordnance Survey maps and today has practical applications in many fields (toponymy, phytosociology, etc.).