Mathematical Treasure: Frobenius's Logarithms of Rheticus's Trig Values

In 1634, Georg Ludwig Frobenius (1566-1645), a German astronomer and former student of Tycho Brahe, published Clavis universi trigonometrica, a text showing applications of spherical trigonometry to astronomy.  Included in this volume was the chapter Canones … logarithmorum, with tables of logarithmic values for the trigonometric values computed by Rheticus in his Canon doctrinae triangulorum (1551).

The image above is presented courtesy of the University of Oklahoma Library.

Index to Mathematical Treasures