Guillaume de l’Isle was the second generation of a cartographic dynasty founded by his father Claude de l’Isle (1644–1720). Claude had four sons, all of whom became geographers. The most remarkable and esteemed of the four was Guillaume, who was reputed to have drawn his first map at the age of nine. He was elected to the Académie des Sciences at the age of twenty-seven, extremely young for an honor that, at any age, was exceptional. Guillaume de l’Isle was a pioneer in scientific cartography combining his advanced knowledge of mathematics and astronomy with cartographic skill. He is today generally acknowledged as the “greatest mapmaker of his time.”9
Guillaume de l’Isle was appointed cartographer to the court of Louis XV. The French court, at this time, was very close to the Society of Jesus. As a consequence of those associations, it is thought that, through the extremely active Jesuit network, Guillaume de l’Isle had received early, verbal reports of Father Kino’s discoveries and of Kino’s well-documented conclusion that, after all, California was really a peninsula.
In this rare first edition of his map of North America, the otherwise punctilious de l’Isle equivocates on the issue of California as an island or a peninsula. California is drawn almost connected to the mainland but not quite. In this particular case, the esteemed cartographer fudged the issue, leaving the viewer to his own conclusions. This is the first map made since 1625 on which California appears to have been reconnected to the continent. More typical of de l’Isle’s careful and conservative approach are the large blank spaces of unexplored northwest America, clearly indicating the limits of knowledge at that time.
It was not until 1701 that Father Kino himself mapped his discovery that California was indeed part of continental America. His map manuscript of that date, showing California as a peninsula, has been lost but copies of it made in Spain were sent to Jesuits in Paris. His discovery was published in 1705 as a map titled Passage par terre A la Californie in the Jesuits’ popular mission magazine Lettres Edifantes and later in the order’s scientific journal Mémoires de Trévoux.10
9. Seymour I. Schwartz and Ralph E. Ehrenberg, The Mapping of America (New York: Abrams, 1980), 133. ↑
10. Ibid., 134. ↑