First edition of Kern's important illustrated German treatise on the practical art of gauging wine casks, a remarkable vernacular work bringing geometry directly into commerce and the wine trade. With provenance from the Library of Owen Gingerich. Completed on 1 April 1531, Kern himself announces its novelty on the title-page, claiming that it is never before printed or issued (dergleichen noch nie getruckt oder außgangen). A wine cask became a commercial object only after its capacity had been determined, and this Visierbuch (gauging book) addresses precisely the practical art by which an irregular barrel could be measured with a graduated Visierrute (gauging rod) and converted into local units of capacity. Written in Early New High German, with Latin mathematical headings, the work identifies its author in both the dedication and closing verses as Ulrich Kern von Freysing, Rechenmeyster und teutscher schreiber (Ulrich Kern of Freising, reckoning-master and German scribe). The dedication to the merchant Hans Volmar of Rottweil reveals the intended audience: merchants, coopers, and tax officials whose livelihood depended upon accurate measurement rather than abstract mathematics. Kern also acknowledges his teacher, Christoff Rudolff of Jauer, author of the first German algebra book and commonly credited with introducing the radical sign, placing the work firmly within the Rechenmeister (reckoning-master) tradition. The printer's family name will not pass unnoticed by any scholar or lover of early printing. Peter Schöffer the Younger was the son of the celebrated Mainz printer Peter Schöffer the Elder, Gutenberg's apprentice and collaborator; he was also the grandson of Johann Fust, Gutenberg's primary financier. The younger Schöffer carried this remarkable printing dynasty into the Reformation era, working successively in Mainz, Worms, Strasbourg, Basel, and Venice. This volume was printed during Schöffer's Strasbourg partnership with Johann Schwintzer, at a moment when practical mathematical knowledge previously transmitted through local teaching and workshop practice was increasingly finding durable printed form. Kern's insistence on adapting the measuring rod to the different weights and measures of individual regions makes the book particularly revealing of the problem it sought to solve: applying a common geometrical method across a commercial world still governed by highly local systems of capacity. The large woodcut printer's device on the colophon leaf is notable in its own right. Signed with the monogram "HG" and traditionally attributed to Hans Baldung Grien, it is Schöffer's elaborate 1531 device, incorporating the family arms and flanked by shepherds and a richly dressed couple. Schöffer reused the block in later publications, including the "Rerum musicorum opusculum" printed with Matthias Apiarius in 1535.