Fincke
# Thomas Fincke

### Born: 6 Jan 1561 in Flensburg, Denmark (now Germany)

Died: 24 April 1656 in Copenhagen, Denmark

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**Thomas Fincke** attended a school in Flensburg until he was 16. After this he spent five years studying at Strasbourg. He then attended seven universities over the next five years; Jena, Wittenberg, Heidelberg, Leipzig, Basel, Padua and Pisa. Only in Padua did he spend a number of years.

He studied medicine in Basel and he practised as a doctor from 1587 until 1591. The first three of these years were spent in medical practise in his home town of Flensburg.

In 1591 Fincke became professor of mathematics at Copenhagen. He became professor of rhetoric at Copenhagen in 1602, then the following year professor of medicine.

His most famous book *Geometriae rotundi* (1583), was intended as a textbook and the reader is referred to Regiomontanus for more details. Based on works of Ramus from whom he took the word 'radius', the book introduces the terms 'tangents' and 'secants' and Fincke devised new formulas such as the law of tangents.

Fincke's book was recommended by Clavius, Napier and Pitiscus all of whom adopted much from it. His other books on astronomy and astrology are of much less interest despite the fact that he was in touch with Brahe and Kepler.

Erasmus Bartholin was Fincke's grandson.

**References (3 books/articles)**

**References elsewhere in this archive:**

Tell me about trigonometric notation

**Other Web sites:**

Rice University, USA

JOC/EFR December 1996