8 Biographical Memoir of the late Frledrich Hoffmann. 



of country ; the field of his observations was at the same time 

 enlarged in its internal contents, as well as external limits. 

 Hoffmann extended it westwards to the slate mountains of the 

 Rhine (1824) ; he devoted his attention likewise to the north- 

 western branches of the German hilly country, between Miin- 

 8ter and Bentheim (1825) ; he afterwards investigated the 

 Erzgebirge and the Fichtelgebirge ( 1 826) ; and finally he in- 

 cluded in his survey the districts between the Hartz and the 

 Thiiringer Wald (1827). The range of connected observations 

 was terminated after eight years methodical investigation. 

 From year to year, he had already delineated the results he 

 obtained on maps, but these now required an explanation ; and 

 it was necessary that the whole treasures of information ac- 

 quired should be transferred as common property to the science 

 of geology. 



Leisure was now given him by the minister for public in- 

 struction, to prepare in Berlin, from 1827 to 1829, his great 

 work entitled " Uehersicht der orographischen und geognos- 

 ilschen Verhdltnisse vom nordwestUchen Deutschland^ (General 

 View of the Orographical and Geognostical relations of North- 

 western Germany), Leipzic, 1830, accompanied by a geognos- 

 tical atlas. The territory over which the investigations ex- 

 tended, amounts to not less than 650 square geographical miles ; 

 and a glance over the beautiful general index map, at once 

 shews an extraordinary complication of extremely difficult re- 

 lations. It was only by dint of indefatigable industry, and en- 

 tire devotion to the object, that a single individual could, in so 

 short a time, have perfected so comprehensive an undertaking. 

 It is founded on such a multitude of separate observations as 

 could only have been collected by indomitable perseverance, 

 and unremitting constancy. But in Hoffmann's case the mass 

 of details did not interfere with broad and talented general 

 views. His connected and comprehensive representation of Che 

 form of the surface of the country, which was the result of 

 more than 2000 measurements of heights, and his descriptions 

 of the most intricate geognostical phenomena of that compli- 

 cated district, were characterised by the most luminous order ; 

 and all bore distinct relation to the general question of the for- 

 mation of the earth, a subject which received not unimportant 



