"A highly-skilled diamond point engraver was responsible for the intricately rendered map depicting the course of the Rhine river from Mainz to Utrecht, drawn after an illustrated map published in Cologne in 1555 by Caspar Vogel, a noted mathematician and cartographer. This particularly large and elaborate beaker would have been filled with wine and passed around at festive occasions. Both decorative and fuctional, the prunts on the stem may have steadied a greasy-fingered drinker’s grip on the glass at a time when forks were not commonly used. " [http://www.metmuseum.org/art/collection/search/188923]