Carte Reduite de l' OCEAN OCCIDENTAL Contenant Partie des Costes d' Europe et d' Afrique... M DCCLXVI.

An decorative maritime chart, by the one of the greatest French hydrographers of the 18th century.
In the context of the war at the end of the 18th century, and of the rivalry between the French and British Navy, maritime atlases, were strategic tools, and this “Hydrographie Françoise” more so than any other, because its purpose was to provide the best maritime charts for the French ships that were fighting on the American side against the British.

These atlases were not only the kind to be kept in a library, but precious tools, based on the observations of the travelers and continuously improved upon.
The captions explain that the maps were created using the latest technology of the day that could measure longitude (maritime clocks).