Theoretical Cartography and the Sea of the West or Mer de l’Ouest

The idea of a great inland sea occupying a vastthough perhaps not so far as the 16th century
part of the American west and opening into theVerazanno’s Sea.
Pacific attained the height of its popularity in the
middle part of the 18th century under theJanvier's 1762 Map of North America Showing
patronage of the influential French cartographersBuache's Sea
Guillaume de l’Isle and Phillipe Buache. UnderThe next incarnations of the Sea of the West
Buache and De l’Isle’s influence the Sea– and perhaps it fullest realization – came
of the West, Mer de L’Ouest, or Baye dethrough the work of the aforementioned
l’Ouest reached its fullest expression andGuillaume de l’Isle and his brother in law
commonly appeared on maps from about 1740Philippe Buache. In the early 17th century it
to 1790.became increasingly important for French and
The source of Sea of the West, however,English settlers along the northeastern coasts of
precedes both Buache and De l’Isle byNorth America to find a passage to the Pacific in
several hundred years. The idea of a Sea of theorder to compete with the Spanish for the
West is intimately related to the hope of either alucrative East India trade. Both nations sent out
Northwest Passage or a River passage from theseveral expeditions both by sea and by river. By
Atlantic to the Pacific. Such a passage wasthis time, most agreed that an Arctic route was
actively sought after almost from the earliestunfeasible and instead turned their attention to the
days of American Exploration. The idea had at itslake and river systems of the continent. Some
core the commercial interests of British andbelieved they would find a river system extending
French traders who, unlike the Spanish, had nowestward from the Hudson Bay along the
easy access to the Pacific and the rich trade withpassage mapped out by Juan de Fuca. Others
Asia.postulated a more southerly route through the
Lake of the Woods and Lake Winnepeg. Still
Munster's iconic 1841 Map of America. Verrazano'sothers believed that a route could be found by
Sea is seen extending from the north towardsfollowing the Missouri River.
Carolina.Such was the competition to get to the Pacific
In it most embryonic form, the Sea of the Westthat, when De l’Isle and Buache
can be associated with Verrazano’s sea. This“discovered” the Sea of the West, they
great sea, pictured here in Munster’s classicchose to keep it a secret for the benefit of
1540 map of the Americas, was identified by theFrance and never published it in any of their
Italian navigator Verrazano. Sailing along Northworks. It was left up to the competing map
Carolina’s Outer Banks in 1524, Verrazanopublisher Nolin to abscond with a copy of De
saw the sound on the eastern side of the isthmusl’Isle’s map and publish the first Buachian
and postulated that it must be the Pacific.“Sea of the West” map. De l’Isle
. . . where was found an isthmus a mile in widthsubsequently filed a law suit against Nolin for
and about 200 long, in which, from the ship, wascopyright infringement,
seen the oriental sea between the west andIl (Nolin) a represente une Mer a l’Occident de
north. Which is the one, without doubt, which goesla Louisiane, qu’il appelle Mer de l’Ouest.
about the extremity of India, China and Cathay.Cette mer estoit une de mes decouvertes, mais
We navigated along the said isthmus with thecomme il n’est pas toujours a propos de
continual hope of finding some strait or truepublier ce que l’on scait, ou que 1 ‘on croit
promontory at which the land would end towardsqavoir, je n’ai pas fait graver cette Mer sur
the north in order to be able to penetrate toles ouvrages quej’ai rendus publics, ne voulant
those blessed shores of Cathay …pas que les Etrangers profitassent de cette
This concept was taken up by variousdecouverte quelle qu’elle pft estre, avant que
cartographers back in Europe and, subsequently, al’on eut reconnu dans ce Royaume si l’on
great indentation along the western coast ofen pourroit tirer quelque avantage..
America starting just north of California was aEven so, the damage was done and the Sea of
common characteristic of many early maps ofthe West began to appear on a number of
the continent. Even in the 1670s, when Johninfluential maps of the period.
Lederer made his famous explorations of VirginiaOf course, one wonders at De l’Isle and
and North Carolina, most colonial settlers believedBuache’s sources. On this we have some
that the western sea was only about 10 or 15certain evidence and a great deal of speculation.
days inland from the coast.Reports from American Indians of a salt sea far
Nonetheless, Verrazano’s Sea was largelyto the west were hardly uncommon in the 18th
discredited in the late 18th century whencentury. De l’Isle would have had access to
prominent cartographers like Ortelius, Mercator,numerous missionary reports that were, at the
Hondius, and Blaeu removed it from their maps. Ittime, streaming into Paris from the new world. At
was not until the 17th century that it began tothe very least, he would have had access to the
reappear on maps though reformatted to anarrative of Lahonton (who heard about the
reduced size and moved farther west.Great Salt Lake from his American Indian Guides),
Juan de Fuca’s legend, the De Fonte letter,
Jansson's 1631 Map of America showing athe influential though possibly fabricated tale of the
mysterious inlet...American Indian traveler Moncacht-Ape, as well as
The next serious first hand evidence of the Seathe explorations of Pierre de La Verendrye.
of the West appears in the account of Juan de
Fuca’s voyage along the western coast ofVaugondy's 1772 Map of America Showing the
America published by Samuel Purchas in his 1625Sea of the West
book Purchas His Pilgrimes. The veracity of deWith so many sources and such a history, one
Fuca’s account has been the subject ofmight be tempted to ask why De l’Isle and
significant debate over the last 100 years or so.Buache claim to have “discovered” the
Most argue that de Fuca’s account wasSea of the West. The stems from the a
fabricated by the Englishman Michael Lok tocartographic approach embraced by Buache.
promote his own ideas of a Northwest Passage.Cartographers had the difficult job of piecing
However, we find a grain of truth in the narrative.together legends, missionary reports, astronomical
De Fuca was supposedly a Greek Captain activeobservations, and nautical references into a
in the Americas in the late 1500s. Colonial recordscohesive whole. It was their job to present the
to indicate that such a figure did in fact exist andknown world in a comprehensible manner. Even
was an active pilot in New Spain from about 1585with reports from navigators and missionaries
to 1600. De Fuca’s account does ringcoming in from all over the world – much was
somewhat of truth if we assume that he actuallyunknown and much else was unreliable. In these
sailed into the strait now named after him:instances cartographers resorted to a number of
…until he came to the Latitude of fortie sevendifferent strategies. Some filled the space with
degrees, and that there finding that the landsketches, drawings, text or cartouches. Others
trended North and north-east with a broad inlet ofsimply left unknown areas blank. Some coped the
sea, between 47 and 48 degrees of Latitude; hespeculations of other cartographers. By early 18th
entered thereinto, sayling therein more thancentury, a new movement had evolved in France
twenty days, and found that Land trendingto address these problems, it was called
sometime North-west and North-east, and North,“theoretical cartography”. Buache was the
and also East and South-eastward, and veryleading theoretical cartographer of his day.
much broader Sea than was at the said entrance,Theoretical cartography attempted to used
and that he passed by divers lands in thatknown geographic patterns and scientific theories
sayling…to fill in blank spaces when little else was known.
Regardless of any actual veracity De Fuca’sThe Mer de la Ouest is the perfect example
account may or may not have, what is importantThough a salt water inlet from the Pacific had long
for our purposes is the effect this report had onbeen speculated upon and hoped for, Buache and
European cartographers who widely trusted it. InDe l’Isle embraced the theory because it
accounting for De Fuca’s 20 days of sailing,supported both the ambitions of the French
European cartographers, began mapping a largecrown in the New World and the theoretical
open inlet extending well into the continent –geographic theory that Buache was developing.