Specialcharte von Livland in 6 Blättern.., 1839

(Special map of Livland in 6 sheets: Edited and published thanks to the Livonian Nonprofit and Economic Society after Struve’s astronomical- trigo- nometric survey and the complete special measurements drawn by C. G. Rücker; engraved in the topographical depot of the Imperial General Staff), printed in St. Petersburg, published in Dorpat. At the time it was the most accurate map of the area, with nearly 4,600 place names. Rücker began compiling a new Livonian atlas based on astronomical- trigonometric survey conducted by German-born astronomer Struve, who published, in 1831, “Beschreibung der Breitengradmessung in den Ostseeprovinzen Russlands” (Description of Latitude Measurement in the Baltic Sea Provinces of Russia). Rücker’s first map, on this page: “General-Charte von Livland,” 1836;  his last: “General-Karte der Russischen Ost-See-Provinzen Liv- Ehst- und Kurland,” 1846.