RITTER, Francis (died 1641). Horologium horizontale ad poli arctici elevationem l. grad. [Nuremberg: Christoff Lochner, in Verlegung Balthasar Camoxen], 1607
Single sheet, float-mounted and framed (11 x 13 2/8 inches; 23 x 24 4/8 inches). A fine engraved map of the world by P. Troeschel on a gnomonic projection from the North Pole, this map is the central vignette surrounded by 10 others, the title in a frame surrounding the top central vignette of a wind dial, dated 1607, all surrounded by a decorative floriated border.
FIRST EDITION, AND AN EXTREMELY RARE AND VERY UNUSUAL MAP, showing the world projected from the North Pole as if it were the table of a sundial, with the land masses drawn to scale in proportion to their distance from the Pole. The result is a very distorted, though mathematically correct, projection, which can be used to locate local sun time. First published as here in Ritter's "Speculum solis; das ist, Sonnenspiegel. Beschreibung unnd unterricht, derer in das kupffer gestochenen sonnenuhren, in welcher der gantze lauff der sonnen, unnd dess mondten durch deroselben schatten zu sehen ist", in the later edition of 1610 the map is much larger and was subsequently re-issued in that format.
The other vignettes depict alternative ways in which other civilisations have recorded the passage of time. Shirley 270; Woodward, David. 'Early gnomonic projection' in Mapline no. 13 (March 1979) p. 1-2