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Guillaume Delisle

Guillaume Delisle is a science topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Guillaume Delisle rather than just read about it. In short: Guillaume Delisle, also spelled Guillaume de l'Isle, or Guillelmo Delille (French pronunciation: [ɡijom dəlil]; 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).

Guillaume Delisle — main illustration
Guillaume Delisle — illustration

Key takeaways

  • Guillaume Delisle belongs to science; place it in that map before memorising details.
  • Learn the definition first, then one example that makes the definition concrete.
  • Connect Guillaume Delisle to a quantity you can measure, compute or draw — that is where exam questions come from.
  • Reproduce the core statement of Guillaume Delisle from memory before moving on to harder problems.

Reference excerpt

Guillaume Delisle, also spelled Guillaume de l'Isle, or Guillelmo Delille (French pronunciation: [ɡijom dəlil]; 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. 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.

Legacy After Guillaume Delisle's death in 1726, his widow tried to preserve the workshop and protect the family. She appealed to the king with the help of the abbot Bignon, the king's librarian and president of the academies. By that time, Guillaume's brothers Joseph-Nicolas and Louis had already left France to serve Peter the Great in Russia. The youngest Delisle, Simon Claude, lacked practical knowledge in cartography; he asked for the king's help in finding him an associate. The Delisle workshop was bequeathed to Philippe Buache. Dutch cartographer Jan Barend Elwe reissued maps by Delisle in the late 18th century.

Maps

Louisiana

… excerpt ends here. Continue reading the full article.

Illustrations

Guillaume Delisle illustration
Guillaume Delisle: 1700 map by De L'Isle of North America, reissued by Covens and Mortier in 1708.
1700 map by De L'Isle of North America, reissued by Covens and Mortier in 1708.
Guillaume Delisle: Delisle's 1718 Carte de la Louisiane
Delisle's 1718 Carte de la Louisiane
Guillaume Delisle illustration
Guillaume Delisle illustration

Worked examples

Example 1 — a first encounter with Guillaume Delisle

Start with the simplest possible case. Write down what Guillaume Delisle claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In science, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Guillaume Delisle before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Guillaume Delisle ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Guillaume Delisle

In research
Guillaume Delisle appears in science research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry
Engineering practice reuses Guillaume Delisle in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom
Guillaume Delisle is common in secondary-school and first-year university syllabi. It links to neighbouring topics 1675 births, 1726 deaths, 17th-century French cartographers, so understanding it makes those chapters shorter.
In everyday life
Look for Guillaume Delisle outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.
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How to study Guillaume Delisle in 20 minutes

  1. Read the reference excerpt below once, without taking notes.
  2. Close the page and write down what Guillaume Delisle means in your own words.
  3. Compare your version with the excerpt and mark what you missed.
  4. Work through the three examples above with pen and paper.
  5. Explain Guillaume Delisle out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Guillaume Delisle in simple terms?

Guillaume Delisle, also spelled Guillaume de l'Isle, or Guillelmo Delille (French pronunciation: [ɡijom dəlil]; 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 Deli…

Why does Guillaume Delisle matter?

Because it connects several science ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Guillaume Delisle?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Guillaume Delisle.

Tags

  • 1675 births
  • 1726 deaths
  • 17th-century French cartographers
  • 18th-century French cartographers
  • Globe makers
  • Historic maps
  • Historical geography of Iran
  • Members of the French Academy of Sciences
  • People of the Regency of Philippe d'Orléans

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