Mathematical Treasure: Hieronymus Ditzel’s Geographiae

Jerome [Hieronymus] Ditzel (1642–1710) was a German geographer, astronomer and mathematician. In his Geographiae, published posthumously in 1716, a section on requisite mathematics is included for the reader. The frontispiece shows the author revealing the  “hand-coded” secrets of his subject.

The material on mathematics begins with a consideration of squared numbers.

The discussion of geometry opens with a consideration of the sphere.

These images are presented courtesy of the John Carter Brown Library, Brown University. The full volume may be read here.

Index to Mathematical Treasures