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Mercator, Nicolaus [Niklaus Kauffman]

1. Dates
Born: Eutin (?), Schleswig-Holstein, ca. 1619
Died: Paris, 14 Jan 1687
Dateinfo: Birth Uncertain
Lifespan: 68
2. Father
Occupation: Schoolmaster
Martin Kauffman was probably a shoolmaster at Oldenburg, Holstein.
No information on financial status.
3. Nationality
Birth: Eutin [?], Schleswig-Holstein, then Denmark
Career: England
Death: Paris, France
4. Education
Schooling: Rostock, M.Phil. (list as M.A.), Leiden
1632, matriculated at Univ. of Rostock. 1641, received M.Phil. I assume a B.A.
Studied for a short time at Leiden.
5. Religion
Affiliation: Lutheran : Lutheran (assumed)
6. Scientific Disciplines
Primary: Mathematics, Astronomy
Subordinate: Navigation, Astrology
While at Copenhagen, Mercator produced several textbooks on elementary astronomy, geography, and spherical trigonometry. Later he did a Latin translation of Kinckhuysen's Dutch Algebra. His Logarithmotechnia, 1668, with a series for calculating logarithms, spurred Newton to set his methods down in De analysi.
Mercator's Hypothesis astronomia nova, 1664, combined Kepler's ellipses with his vicarious hypothesis. His Institutiones astronomicae, 1676, gave a good exposition of contemporary astronomical theory. He exchanged letters with Newton on lunar theory, and he demolished Cassini's method of determining the line of apsides of a planetary orbit from three solar sightings.
Mercator advertised himself as an expert in the theory of Gerard Mercator's map projection, and he published a paper on navigation in the Philosophical Transactions.
He composed a manuscript Astrologica rationalis, which was never published. Described in detail in General Dictionary.
7. Means of Support
Primary: Academia, Schoolmastering, Patronage
1642, on the philosophy faculty at Univ. of Rostock.
1648-1654, on the faculty at Univ. of Copenhagen, was forced to leave when the university closed due to plague.
By 1660, he was in England suffering monetary difficulties. He supported himself tutoring in mathematics, received some patronage, and tried to make some money from his marine chronometer.
1682, he accepted the commission from Colbert to plan the waterworks at Versailles, moved to France, and died after a few years.
8. Patronage
Types: Academic, Scientist, City Magistrate, Government Official
He was taken on at Rostock through the influence of the Hebraist, Hein.
Cosmographia (1651), Trigonometria sphaericorum logarithmica (1651), and Astronomica sphaerica (1651) all are dedicated to the city council of Copenhagen.
Cromwell noticed his tract on calendar improvement (1653), but it is not known whether he was invited to England because of it.
Moray acted as his patron at the Royal Society. He was responsible for his nomination, and saw to it that Mercator received the assignment to make regular barometric measurements for the Society.
He presented a large clock which showed the inequality of the sun's motion from its apparent motion to King Charles II, who is said to have understood and commended it but gave Mercator nothing for it.
1676, Hooke unsucessfully proposed him as mathematical master at Christ's Hospital.
1669, Collins, at Seth Ward's suggestion, commissioned him to write a Latin version of Kinckhuysens Dutch Algebra.
Colbert commissioned him to plan the waterworks at Versailles, but they had a falling out sometime before Mercator died.
9. Technological Involvement
Types: Instruments, Navigation, Hydraulics
1666, he designed a pendulum marine chronometer.
1669, he invented an efficient method for sailing into the wind and improved his clock.
10. Scientific Societies
Membership: Royal Society
On the strength of his marine chronometer (and with Moray's help) he was elected into the Royal Society in 1666, though he did not participate until 1669.
  1. not in the DNB.
  2. J.E. Hofmann, Nicolaus Mercator (Kauffman), sein Leben und Wirken, vorzugsweise als Mathematiker (in Academie der Wissenschaften und der Literatur in Mainz [Abh. der Math.-Nat. Kl., no. 3, 1950]) [Swain QA29.M5H7] John Aubrey, Letters... and Lives of Eminent Men, 2 (London, 1813), 450-1, 473. [DA447.A3 W2 v.2]
  3. "Mercator, Nicolas," in Pierre Bayle, A General Dictionary Historical and Critical, tr. John P. Bernard, Thomas Birch, and John Lockman, 10 vols. (London, 1734-41), 7, 537-9.
Compiled by:
Richard S. Westfall
Department of History and Philosophy of Science
Indiana University

Note: the creators of the Galileo Project and this catalogue cannot answer email on geneological questions.

1995 Al Van Helden
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