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astronomy

John Keill

John Keill is a astronomy 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 John Keill rather than just read about it. In short: John Keill FRS (1 December 1671 – 31 August 1721) was a Scottish mathematician, natural philosopher, and cryptographer who was an important defender of Isaac Newton. Biography Keill was born in Edinburgh, Scotland on 1 December 1671.

John Keill — main illustration
John Keill — illustration

Key takeaways

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

Reference excerpt

John Keill FRS (1 December 1671 – 31 August 1721) was a Scottish mathematician, natural philosopher, and cryptographer who was an important defender of Isaac Newton.

Biography Keill was born in Edinburgh, Scotland on 1 December 1671. His father was Robert Keill, an Edinburgh lawyer. His mother was Sarah Cockburn. His brother, James Keill, became a noted physician. Keill studied at Edinburgh University under David Gregory. In 1692, he obtained his bachelor's degree with a distinction in physics and mathematics. Keill then attended Balliol College, Oxford, obtaining an MA on 2 February 1694. After being appointed a lecturer in experimental philosophy at Hart Hall, Keill started giving lectures and performing experiments based on Newton's findings. He instructed his students on the laws of motion, the principles of hydrostatics and optics, and Newtonian propositions on light and colours. In 1698, Keill published Examination of Dr. Burnet's Theory of the Earth. His volume contained scientific attacks on Burnet, René Descartes, Baruch Spinoza, Thomas Hobbes and Nicolas Malebranche. This publication, along with his teaching, gained Keill notice in the English academic community. In 1700, he was elected a Fellow of the Royal Society. However, after failing to get an academic appointment at Oxford in 1709, Keill left the university to seek a government position. At Hart Hall the innovatory nature of Keill's demonstrations, and his teaching, were continued after 1710 by his student John Theophilus Desaguliers. The methods both used were instrumental in popularising Newtonian ideas and making them more accessible. In 1709, Keill was appointed treasurer of a charitable fund to resettle war refugees from the German states. He accompanied at least one group of German refugees to the British Province of New York. In 1711, Keill accepted the position of decypherer to Anne, Queen of Great Britain. His responsibilities included explaining old manuscripts to the sovereign. In 1712, Keill returned to Oxford as Savilian Professor of Astronomy. On 9 July 1713, he was awarded the DM degree. In his later years, Keill became involved in the controversy regarding Gottfried Leibniz's alleged plagiarisation of Newton's invention of calculus, serving as Newton's chief defender. However, Newton himself eventually grew tired of Keill as he stirred up too much trouble. In 1717, Keill married Mary Clements, a woman 25 years his junior and the daughter of an Oxford bookbinder. The marriage created great scandal at the time as Clements was from a lower class.

On 31 August 1721, Keill died in London from a sudden illness, possibly food poisoning. It was stated in the old Dictionary of National Biography that Keill left no will. His will is referenced in the Oxford Dictionary of National Biography and is held by The National Archives. It was executed on 12 January 1720 and was proved in the Prerogative Court of Canterbury in October 1721. He spent £500 to his household furniture and plate to his wife and his books, instruments and other money in trust for his son.

Principal publications

An Examination of Dr. Burnet's Theory of the Earth. Oxford: 1698. Introductio ad Veram Physicam seu Lectiones Physicae. Oxford: Thomas Bennet, 1702. Trigonometriae Planae & Sphaericae Elementa. Oxford: Henry Clements, 1715. Item de Natura et Arithmetica Logarithmorum tractatus brevis. Oxford: Henry Clements, 1715. Introductio ad Veram Astronomiam seu Lectiones Astronomicae. Oxford: Henry Clements, 1718. Keill's publisher at Oxford, Henry Clements, sometimes bound Keill's Trigonometriae and Logarithmorum with Federico Commandino's translation of Euclid's Elements. This volume appeared as: Euclidis Elementorum Libri Priores Sex. Oxford: Henry Clements, 1715. After Keill's death, the Verbeek brothers collected Keill's work into a single volume. This volume appeared as: Introductiones ad veram Physicam et veram Astronomiam. Leiden: Jan en Hermanus Verbeek, 1725. This book also contained Keill's long papers De Legibus Virium Centripetarum and De Legibus Attractionis, aliisque Physices Principiis. All of these works were very popular; they appeared in England and the Continent in many editions from many publishers, in Latin, English, and Dutch.

Editions Introductiones ad veram physicam et veram astronomiam (in Latin). Leiden: Johannes Verbeek & Hermanus Verbeek. 1739. Introduction to the true astronomy, or, astronomical lectures, read in the astronomical school of the University of Oxford (in French). Paris: Hippolyte-Louis Guérin & Jacques Guérin. 1746.

References

External links

Keill's MacTutor biography Archived 4 March 2016 at the Wayback Machine "Keill, John" . Dictionary of National Biography. London: Smith, Elder & Co. 1885–1900. An examination of Dr. Burnet's theory of the Earth – full digital facsimile of Keill's 1698 book at Linda Hall Library

Illustrations

John Keill illustration
John Keill illustration
John Keill illustration

Worked examples

Example 1 — a first encounter with John Keill

Start with the simplest possible case. Write down what John Keill claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In astronomy, 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 John Keill 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 John Keill 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 John Keill

In research
John Keill appears in astronomy 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 John Keill 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
John Keill is common in secondary-school and first-year university syllabi. It links to neighbouring topics 1671 births, 1721 deaths, 18th-century Scottish mathematicians, so understanding it makes those chapters shorter.
In everyday life
Look for John Keill 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 John Keill in 20 minutes

  1. Read the reference excerpt below once, without taking notes.
  2. Close the page and write down what John Keill 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 John Keill out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is John Keill in simple terms?

John Keill FRS (1 December 1671 – 31 August 1721) was a Scottish mathematician, natural philosopher, and cryptographer who was an important defender of Isaac Newton. Biography Keill was born in Edinburgh, Scotland on 1 December 1671.

Why does John Keill matter?

Because it connects several astronomy 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 John Keill?

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 John Keill.

Tags

  • 1671 births
  • 1721 deaths
  • 18th-century Scottish mathematicians
  • Alumni of Balliol College, Oxford
  • Alumni of the University of Edinburgh
  • British fellows of the Royal Society
  • Natural philosophers
  • Savilian Professors of Astronomy
  • Scientists from Edinburgh
  • Scottish astronomers

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