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Mathematical Treasure: Peter Ryff’s Questiones Geometricae

Author(s): 
Frank J. Swetz (The Pennsylvania State University)

Peter Ryff (1552–1629) was a Swiss physician and mathematician. His Questiones Geometricae of 1621 clarified some issues involving geometry that were raised by an attack on Euclid’s Elements undertaken by Peter Ramus (1515–1572) in 1569.

Title page for Peter Ryff's 1621 Questiones Geometricae.

Ryff’s first question dealt with the definition of “geometry”.

First page of Questiones Geometricae by Peter Ryff (1621).

A few pages later, Ryff explored compass constructions.

Pages 12-13 of Questiones Geometricae by Peter Ryff (1621).

The images above are provided courtesy of Bamberg State Library. A full digitization of this book is available here.

Index to Mathematical Treasures

Frank J. Swetz (The Pennsylvania State University), "Mathematical Treasure: Peter Ryff’s Questiones Geometricae," Convergence (April 2022)