Vol. 70.] ANNIVERSARY ADDRESS OF THE PRESIDENT. lxv 



Credner sought a wider sphere of labour by journeying to the 

 United States, where he spent four years, acting as a mining 

 expert in the search for gold, but taking every opportunity for 

 widening his knowledge of geological science. At a time when road 

 and rail had not yet opened up the country, he traversed the whole 

 of the States between New York and Nevada, and from Michigan 

 to Georgia, recording his observation in a number of valuable 

 memoirs. 



Returning to his native country after his long wanderjahr, 

 he, in 1869, became a privat-docent under Naumann in the 

 University of Leipzig ; and in the following year, when Zirkel 

 succeeded Naumann, he was appointed Professor Extraordinarius, 

 to teach Historical Geology and Palaeontology, becoming a full 

 Professor in 1877. 



One, of Credner' s first labours in his new position was to prepare 

 his well-known and admirable text-book 'Elemente der Geologic" 

 which, during the lifetime of its author, passed through no less 

 than eleven editions, each of which was revised, expanded, and 

 brought up to date by the indefatigable Professor. 



Credner was now, however, to enter upon a still wider field of 

 labour. Saxony, the birthplace of Mining Geology, had already 

 been twice mapped geologically ; first, at the close of the eighteenth 

 century under the auspices of the illustrious Werner himself, and 

 secondly, between 1835 and 1845, by Naumann and Yon Cotta. But 

 in 1872, the Government having decided on the preparation of a 

 new and more detailed map, Credner was chosen to organize and 

 direct the staff of surveyors. Between the date of his appointment 

 and the year 1899, Credner with his able assistants issued no less 

 than 127 sheets of the map as well as the accompanying memoirs, 

 and in 1908 he was able to issue his beautiful geological map of the 

 whole country on a reduced scale. 



In connexion with his work upon the Geological Survey, Credner 

 wrote notable papers in scientific journals dealing with many 

 important questions, such as his views on the Saxon granulite 

 formation, the Oligocene and other Tertiary strata, the phosphatk- 

 deposits, and the glacial phenomena of the country. But these 

 labours did not exhaust his energies, for between the years 1881 

 and 1894 he issued, in ten parts, his important palaeontological 

 memoir on the Stegocephali and Saurians of the Rotliegende of 

 the Plauenschen Grund near Dresden ; while between 1897 and 

 1903 he devoted much attention to the study of earthquakes, 



vol. lxx. e 



