Guillaume Delisle, also spelled Guillaume de l'Isle, (; 28 February 1675, Paris – 25 January 1726, Paris) was a French cartographer known for his popular and accurate maps of Europe and the newly explored Americas.
Childhood and education
Delisle was the son of Marie Malaine and Claude Delisle (1644–1720). His mother died after childbirth and his father married again, to Charlotte Millet de la Croyère. Delisle and his second wife had as many as 12 children, but many of them died at a young age. Although the senior Delisle had studied law, he also taught history and geography. He had an excellent reputation in Paris’ intellectual circles, and served as a tutor to lords. Among them was the duke Philippe d’Orléans, who later became regent for the crown of France, and collaborated with Nicolas Sanson, a well-known cartographer. Guillaume and two of his half-brothers, Joseph Nicolas and Louis, ended up pursuing similar careers in science.
While his father has to be given credit for educating Guillaume, the boy showed early signs of being an exceptional talent. He soon contributed to the family workshop, by drawing maps for his father's historical works. Some have questioned the authorship of these first maps, saying that Delisle only copied what his father had done before him. In order to perfect his skills, Guillaume Delisle became the student of the astronomer Jean-Dominique Cassini. Early on he produced high-quality maps, the first being his Carte de la Nouvelle-France et des Pays Voisins in 1696.
Career
At 27, Delisle was admitted into the French Académie Royale des Sciences, an institution financed by the French state. After that date, he signed his maps with the title of "Géographe de l’Académie". Five years later, he moved to the Quai de l’Horloge in Paris, a true publishing hub where his business prospered. Delisle's progress culminated in 1718 when he received the title of Premier Géographe du Roi. He was appointed to teach geography to the Dauphin, King Louis XIV’s son, a task for which he received a salary. Again, his father's reputation as a man of science probably helped the younger Delisle. Historian Mary Sponberg Pedley says, "once authority was established, a geographer's name might retain enough value to support two or three generations of mapmakers". In Delisle's case, it could be said that his accomplishments surpassed his father's. Up to that point, he had drawn maps not only of European countries, such as Italy, Spain, Germany, Great Britain, Poland, and regions such as the Duchy of Burgundy, but he had also contributed to the empire's claims to recently explored continents of Africa and the Americas.
Like many cartographers of his day, Delisle did not travel with the explorers. He drew maps mostly in his office, relying on a variety of data. The quality of his maps depended on a solid network to provide him first-hand information. Given his family's and his own reputation, Delisle had access to fairly recent accounts of travellers who were returning from the New World, which gave him an advantage over his competitors. Being a member of the Académie, he also kept current with recent discoveries, especially in astronomy and measurement. When he could not confirm the accuracy of a source, he would indicate it clearly on his maps. For instance, his Carte de la Louisiane shows a river that the baron of Lahontan claimed he discovered. As no one else could validate it, Delisle noted a warning to the viewer that it might not exist.
Delisle's search for exactitude and intellectual honesty entangled him in a legal dispute in 1700 with Jean-Baptiste Nolin, a fellow cartographer. On March 8, 1700, De L'Isle accused Nolin (at first not naming him) of having copied proprietary cartographic information from a manuscript globe that he had made for Chancellor Boucherat, which resided in the cabinet of the latter's son. This globe included information that De L'Isle had intentionally not put in print, such as the Sea of the West, because, according to De L'Isle himself, he did not want to make it available to France's competition. De L’Isle wrote of the Sea of the West. Delisle took Nolin to court to prove his plagiarism. In the end, Delisle convinced the jury of scientists that Nolin knew only the old methods of cartography and must have stolen the information from Delisle's own manuscript. Nolin's maps were confiscated and he was forced to pay the court costs of the case. The high scientific quality of the work produced by the Delisle family contrasted with the workshop of Sanson. While Sanson knowingly published outdated facts and mistakes, Delisle worked to present up-to-date knowledge.