La carte de France de Cassini. Une encyclopédie du territoire

A cartographic masterpiece of the 18th century, the Cassini map of France is the first geometrically surveyed map of France on the scale of an entire country. An emblematic historical document, composed of 181 sheets, it is also a monumental work of art, eleven metres wide and twelve metres high. Drawing notably on a major transfer from the IGN to the National Archives, the exhibition retraces the history of the map in a new light.

1. In 2021 and 2025, the French National Institute of Geographic and Forest Information (IGN) transferred to the National Archives the collection of archives related to the Academy's map of France, better known as the Cassini map of France.

   This remarkable collection comprises calculations, writings, drafts, as well as original copper plates and prints detailing the creation and life of this map between 1750 and the 1950s. This exceptionally rich collection now allows us to unveil little-known aspects of a work of universal scope; a work conceived by four generations of astronomers and cartographers: the Cassini family. The Art of Science As the first map surveyed "geometrically" on the scale of an entire country, the Kingdom of France, at the time the most powerful and populous in Europe, its realisation is admirable in many respects. Firstly, it is the fruit of continuous state will, with Louis XIV and Colbert, Louis XV, and then Bonaparte, initiating and perpetuating the project; even if, from 1756 to 1793, a private company partly financed it. It involved the use of innovative scientific techniques, for both method and instruments, linking it to the creation of the Academy of Sciences in 1666 and the Paris Observatory in

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5. It arose from the perseverance of scholars who implemented it until 1815, alongside the dynasty of the four Cassinis from 1669 to

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9. It resulted from meticulous, standardised, sometimes difficult, and very long-term fieldwork, followed by restitution through engraving, from Abbé Picard's surveys in 1668 to the last verified surveys in

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13. Finally, it is extraordinary in its final deployment, in space of course, as the 181 assembled sheets are over twelve metres high and eleven metres wide; but also in time, as almost three centuries elapsed from the first works in 1668 to the ultimate use of the copper plates in the 20th century! An extraordinary adventure The cons