Copper engraving, 550x875 mm, hand-painted in watercolour. Beautiful map of the world showing the magnetic variations of the compass, one of the first French world maps to illustrate magnetic variations.First state of the plate with cartouche depicting the royal coat of arms with the 3 fleur-de-lis.An elegantly drawn and accurately drawn maritime chart of the oceans sailed by French navigators in the 18th century. Designed by J. N. Bellin (1703-1772), who during his more than fifty years of work at the French Hydrographic Service was appointed the first 'Ingenieur hydrographe de la Marine'. This map extends from California to Japan and focuses on the Atlantic and Indian Oceans. France's sphere of influence in the West Indies, Africa and India would generate this interest in compass and wind variations applied to a Mercator projection covering most of the world.By 1765, France had lost most of its overseas empire in America as a result of the Seven Years' War (French and Indian War in America), so knowledge of sea routes was important to maintain what was left. In addition to a wealth of hydrographic information, including small windheads, this beautiful chart features an exquisite cartouche with the French crown surmounting the globe.