Important 18th Century wall map of America, one of the earliest obtainable printed maps to show the Sea or Bay of the West and the earliest wall map of America to show this configuration.
The map is oriented with east at the top, one of only a few maps to present America in this configuration and unquestionably the largest and most decorative.
The source of the modern (18th Century) myth of the Sea or Bay of the West (Baye ou Mer de L'Ouest in French), are manuscript maps by Guillaume De L'Isle, who served as the Royal Geographer to the King of France at the end of the 17th Century and beginning of the 18th Century and is widely regarded as the most important map maker of his time. There is a map in Yale's map collection, which depicts a 16th Century Thames school map of North America with a large, "Branch of the South Sea," which closely resembles De L'Isle's Mer de L'Ouest, and may well be the source of De L'Isle's idea.
At the end of the 17th Century, De L'Isle had access to the best available maps of the interior of North America, which were being provided from a number of missionary sources, as the French Missionaries pushed west of the Great Lakes and the Mississippi River and obtained information from the indigenous Indian tribes. De L'Isle was regularly producing and updating his manuscript maps in an attempt to integrate new and often conflicting information and improve upon the existing maps of North America. Many of his maps can be viewed as drafts, which were discarded in favor of other and considerably different models.
There are several De L'Isle manuscripts in the Bibliotheque Nationale de France, prepared as early as 1696 (dated), that depict this cartographic myth. Interestingly, while De L'Isle was a prolific publisher of printed maps, he never depicted the Sea or Bay of the West on any of his printed maps, which strongly suggests that he was not able to reconcile this information with the best available source information from America. During this same period, Jean Baptiste Nolin, who had in the prior decade collaborated with Vincenzo Maria Coronelli on his monumental globe for Louis XIV and produced a series of highly important maps of North America and its regions, would have also had access to many of the same reports and maps as De L'Isle. Nolin apparently gave greater credence to the concept than De L'Isle.
The earliest printed map to show the Bay of the West is Jean Baptiste Nolin's rare wall map of the world. There are 3 states of the map, according to an upcoming book written by Don McGuirk. The states bear the imprints of Pierre Mortier, David Mortier, and the Covens & Mortier. None of the states are dated, although estimates range from just before 1700 to 1704-07 for the first state, with the Covens & Mortier state being offered from 1721 onwards. It should be noted that De L'Isle sued Nolin for stealing his idea and image of the Mer de L'Ouest for his wall map (see Shirley 605). Being in another country, the Mortier Firm was not subject to French jurisdiction and was therefore not sued. Nolin lost the lawsuit and in his future wall maps was forced to depict a different and smaller Mer De L'Ouest which, interestingly, somewhat resembles Puget Sound.
While the myth of the Sea or Bay of the West temporarily languished, the proliferation of Russian exploration off the Northwest Coast of America after 1740 reinvigorated interest in the region and forced the most prominent map makers of the period to re-examine existing knowledge. During a period between 1750 and 1770, the most prominent French and British map makers advanced multiple and widely varying theories on the Northwest Coast of America. Denis Diderot dedicates several of the 10 maps in his monumental Encylopedie (1779 and after), to a comprehensive survey of the maps proffered by Joseph Nicholas De L'Isle (Guillaume's brother), Philippe Buache, Thomas Jefferys and others. The debate ended with Captain James Cook's and later George Vancouver and Comte Jean de la Perouse's explorations in the late 18th Century.
The Janvier / Longchamps map of America is the first wall map of America to show the Sea of the West. The map is surrounded by decorative vignettes which depict important events in American History. It is noteworthy for both its decorative quality and early depiction of the Sea or Bay of the West, as well as the curious east at the top projection, which may simply have been a convenience for making the map relatively uniform to the sizes of Longchamps wall maps of Asia, Africa, and Europe.