The known unknown land. The history of study of north China in the XIXth century

This article is devoted to the history of Russian hypsometric and geographic investigations of the northern part of China, Mongolia, Manchuria, the Amur and the Ussuri region in the 19th century. The article is based on the analysis of numerous sources from the Russian State Historical Archive, St. Petersburg Branch of the Archive of the Academy of Sciences, Russian National Library, the Library of the Shanghai Zikawei Observatory. The article's methodological framework is objectivity concept, systematically of scientific analysis of archival materials. The considerable attention is paid to H. Fritsche's, Palladius's, N.M. Przhevalsky's and other expeditions. The detailed analysis of a new systematic mapping of the northern part of China, made by the Russian scientists is given. The role of the Beijing Magneto-meteorological observatory in Beijing, as the part of the Russian Academy of sciences, is specially noted. The author considers in details the political and socioeconomic conditions of expeditions.