Geology.- Dechen (Ernst Heinrich Karl von) Geognostische Übersichts-Karte von Deutschland, Frankreich, England und den angrenzenden Laendern, folding hand-coloured engraved map, 650 x 900mm., small hole to blank part of English Channel, lightly browned, the odd small stain, linen-backed and dissected, folding into contemporary shagreen, brass clasp, rebacked, corners worn, rubbed, Berlin, Simon Schropp & Co., 1839.

⁂ Rare. Dechen 'prepared numerous geological maps, which Humboldt described as models in this field and which for long were standard' (DSB). This map is one of Dechen's earliest. It extends from the east coast of Ireland to the Pyrenees, and westwards as far as Vilnius and the eastern edge of the Carpathians. Dechen (1800-1889) was a German geologist, who became director of the Prussian mining department. The mineral Dechenite was named after him by Carl Wilhelm Sigismund Bergemann in 1850.