Mathematical Treasure: Euclid's Elements of Henrik Coets

Henrik Coets (1670-1730), or Henricus Coetsius in Latin, was a Dutch mathematician who wrote several books on geometry, arithmetic, and horology. His Euclidis Elementorum first appeared in 1691.  The images below come from an edition published in the following year, 1692.

The interior title page shows an unidentified classical geometer at work.

Pages 68 and 69 discuss vertical angles of two intersecting lines.

Very little is known about Coets. A list of his publications may be viewed in WorldCat Identities and a few other details via the Consortium of European Research Libraries (CERL) Thesaurus, which uses Hendrik Coets as its primary spelling.

The images above are provided courtesy of Columbia University Libraries. A copy of this work is also available in its entirety in Google Books.

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