URSINUS, Benjamin (1587-1633). Trigonometria cum magno logarithmor[um] canone [And] Magnus canon triangulorum logarithmicus. Cologne: Georg Runge for Martinus Gutt, 1624-1625.

First edition of "the largest table of original Napierian logarithms that were produced" (Tomash). Ursinus was a German mathematics teacher whose earlier publication of a small Napierian logarithm table in his Cursus mathematici practici had aroused Kepler’s interest and eventually resulted in the Rudolphine Tables--which Ursinus as assisted with, as a friend of Kepler. "The book deals with how logarithms were calculated and their use in both plane and spherical trigonometry. The tables, which have a separate title page, are dated a year earlier than the text but were never issued independently" (Tomash). Tomash and Williams U6 and U7.

Quarto (193 x 147mm). Engraved title to first work (some browning, minimal marginal worming to a few leaves). Contemporary vellum labeled in manuscript on spine (front pastedown torn). Provenance: Erwin Tomash (bookplate).