Rheticus, Georg Joachim.

Opus palatinum de triangulis… L. Valentinus Otho principis palatini Friderici IV electoris mathematicus consummavit.

First edition, 4 parts only (of 6), engraved title-page, woodcut initials and tailpieces, woodcut diagrams, some printing in red, woodcut printer’s device below colophon (Vvv5r), Rheticus’s name on b5 partly covered over with a contemporary slip of paper, blank leaves appearing before each part except first, quire P in duplicate, near-contemporary limp vellum, stubs from two pairs of ties, gilt edges, contemporary lettering to spine and number on upper cover, lacking quire L4, title-page slightly worn at extremities, cut close at foredge, partial library ink stamp on title-page, Otho’s name at end of preface partially effaced, some toning and damp staining in places throughout, Q2-3 with large brown stain, upper hinge broken, spine with small hole and creased, folio, (Neustadt an der Weinstrasse: Matthaeus Harnish), 1596

Title, Dedication and preface by LV Otho. - Parts - II: Rheticus, GJ, De fabrica canonis doctrinae triangulorum. 104 (recte 109) p., 1 w. sheet - III: Ill., De triangulis globi cum angulo recto. 140 (right 146) pp., 2 w. ll. (including 1 after p. 102). - IV: Otho, LV, De triangulis globi sine angulo recto libri quinque. 1 sheet, 341 (recte 342) p., 1 sheet with printer's mark, 1 white sheet - V: Ders., Meteoroscopium numerorum primum. 121 (recte 126) pp., 1 page errata.

***Georg Joachim Rheticus (1514-76), fellow student of Conrad Gesner and friend of Melanchthon, was an enthusiastic follower and contemporary of Copernicus. This work is of great historical importance as the first trigonometrical tables ever issued. Unfortunately, the work was unfinished at his death in 1574, but the publication of Rheticus’s work was accomplished by his pupil Valentin Otho in 1596. These trigonometrical tables (as corrected by Bartholomaeus Pitiscus in 1613) were still in use in the early twentieth century.