The first issue of an influential map, the first to show the ‘Mer de l’Ouest’

The first issue of an important map of the North Pacific compiled by Buache from the work of Joseph Delisle, showing the coasts of Asia south to Japan and America to Yucatan.
Delisle spent much of his career in Russia, producing the 'Atlas Russicus' (the first Russian atlas) with Ivan Kyrilov and founding the 'Academy of Sciences of St Petersburg'. He returned to Paris is 1747 with a large map collection, including (unfortunately for the reputation of French cartography) the manuscript of this map of the north Pacific, which he presented to a public assembly of the French Academy of Sciences in 1750. While it showed some important discoveries by the Russians on the Asian side of the Bering Strait, it also included the supposed discoveries of Admiral de Fonte and Juan de Fuca, including a vast inland sea, the 'Mer de L'Ouest', and a waterway stretching from the Pacific almost to Baffin's Bay.
Copied extensively by other French mapmakers, the myth was finally disproved by English explorers James Cook & George Vancouver.