1760 De L'Isle Speculative Map of the North America, the Arctic, and Siberia (Sea of the West)

The 1789 Dezauche edition of Joseph Nicolas De l'Isle's extraordinary 1752 map of North America, Siberia, the Arctic, and the North Pacific. J. N. De L'Isle and Buache drew this map to illustrate their speculations on the feasibly of a Northwest Passage. Cartographically this map is a combination of data absconded from the Russian 'Academy of Sciences' and Buache's speculations on the Northwest Passage. This map is highly significant for its revival of the 'Sea of the West' hypothesis. This is a landmark map in the history of cartography and perhaps the single most influential map of the region issued in the middle of the 18th Century.

When Joseph-Nicholas de L'Isle, younger brother of the better known Guilleme de L'Isle, returned from his tenure at Russian Tzar Peter the Great's Academy of Sciences he decided to publish a compilation of secret cartographic data obtained from previously unknown Russian expeditions to Kamtschaka and the coast of Siberia. These seminal explorations included the discoveries of Aleksei Ilyich Chirikov (Tchirikow), Nicholas de Frondat, and Vitus Bering, among others. De L'Isle produced a ground breaking and largely accurate mapping of the peninsula of Kamchatka and the coast of northeast Asia - shown here. This he presented in manuscript form to the Paris Royal Academie des Sciences in on the 8th of April, 1750. This date appears on all editions of the map.

De L'Isle contracted J. N. Buache, already a prominent cartographic figure due to his introduction of hachures as a method for displaying elevation on a two dimensional plane, to complete the North American part of the map. Buache used the mythical voyages of Admiral de Fonte, Martin Aguilar, and Juan de Fuca as his cartographic source material. The two sides of this map therefore could not be more heavily contrasted, for the mapping of Asia is largely accurate where the mapping of North America is almost entirely fantastical. This map shows the 'Sea of the West,' supposedly discovered by Fuca, as well as the series of lakes, rivers, and canals heading eastward toward the Baffin and Hudson Bays that were purportedly first identified by De Fonte. These include Lac de Fonte, Lac Belle and Lac de Valasco.

The tale of De Fonte' discoveries in the American Northwest are particularly interesting. The De Fonte legend first appeared in a 1706 English publication entitled Memoirs of the Curious. This short-lived magazine published a previously unknown account by a supposed Spanish Admiral named Bartholomew de Fonte. De Fonte is said to have sailed up the Pacific coast of North America in 1640. On this voyage he apparently discovered a series of gigantic lakes, seas, and rivers heading eastward from the Pacific towards Hudson Bay. The De Fonte story relates how, on one of these great inland lakes, he met with a westward bound ship from Boston that must to have come through the Northwest Passage. Today, based upon inaccuracies and falsities, we know the entire De Fonte article to have been a fabrication, however, it set 18th century afire with speculation that a Northwest Passage must indeed exist. Even such luminaries as Benjamin Franklin wrote long defenses of De Fonte. Our map offers an uncommon variant on the De Fonte passage, positioning its western entrada well to the north in order to accommodate the Sea of the West and situating its outlet at the Baffin rather than the Hudson Bay.

By far the most interesting aspects of this map deal with De L'Isle and Buache's treatment of the largely unexplored Pacific Northwest. A magnificent sea, called the Sea of the West or in this case the Baye de L'Ouest, occupies the greater part of the northwestern part of the continent. This body of water, alternatively called the Sea of the West or Mer de l'Ouest, was speculated by Philippe Buache and De l'Isle in the early 18th century based upon wishful thinking, American Indian stories, and the somewhat questionable 16th century explorations of Juan de Fuca. Here Buache gives the Mer de l'Ouest its fullest expression, though he specifically does not connect it to either the factual network of lakes and rivers extending westward form the Hudson Bay or to the speculative De Fonte network just to the north.

On the opposite side of the map, just to the east of Kamchatka there is an unusual body of land reminiscent of the Muller Peninsula, postulated around this time based on sightings of the Aleutian archipelago and their misinterpretation as a single land mass. This supposed island bears a significant resemblance to Gamaland or Compagnie Land as imagined by Sanson c. 1705. A note at the very edge of this land mass claims that it was seen in 1741, suggesting either Vitus Bering or Alexei Chirikov. Both did in fact search for Gama or Compagnie land in this year without significant success. Curiously both Gamaland, the supposed discovery of explorer Jean de Gama, and Compagnie, are also illustrated, well reduced over Sanson's model, just to the east of a malformed Yedo (Yeco) or modern day Hokkaido. In actuality both Gama and Compagnie and presented here reflect preliminary sightings of the Japanese Kuril Islands in 1643 by the Dutch navigators Maerten de Vries and Cornelis Jansz Coen. Vries and Coen were searching for Juan de Gama's discovery which was originally considered to be an island replete with silver and other precious metals.

Along the base of the map the Acapulco to Manila trade route is illustrated according to records dating to the British Baron George Anson's capture of the Spanish treasure galleon Nuestra Senora de Covadonga. The galleon, taken off of Cape Espiritu Santo in 1743 was loaded with silver bullion and, more importantly, charts and maps detailing the routes between Mexico and the Far east used by the Spanish for over 200 years. Knowledge of this route enabled the British navy to disrupt Spanish trade in the Pacific and thus weaken its stranglehold on the Americas. Upon his return to england Anson was hailed as a national hero and made immensely wealthy by his share of the Nuestra's treasure. The impact Anson's exposure of the secret Acapulco – Manila route on the global economy is emphasized in its inclusion in this French map.

A careful examination of this map also reveals much of De L'Isle's political agenda through his carto-advocacy for French interests. Here the sprawling territory of Louisiana stretches from the Rio Grande, inclusive of then Spanish Texas eastwards as far as the Apalaches (Appalachian Mountains). Frances's northern Territories, 'Canada ou Nouvelle France,' extend southwards as far as the Illinois River and eastward to the Appalachian Mountains, inclusive of all five Great Lakes as well as the northern Hudson Valley and Lake Champlain. This political configuration is particularly interesting when considered within the context of the thriving fur trade. Here France dominates the fur-rich northern part of the continent and the Mississippi River, firmly located in the heart of Louisiana, offers easy access to the French port of New Orleans and a route to French markets in Europe. Moreover, it gives preference for possession of the as yet undiscovered potential of a Northwest Passage either through De Fonte routes or through the Sea of the West to France.

This map was published in J. Dezauche's 1789 reissue of G. De L'Isle and P. Buache's Atlas Geographique et Universel.