44 OUTUMSM]. 1 1 1 LD-GEOLOGY PARTI 



features in his mind in their natural proportions ; he has 

 the original sketch to refer to and to recall impressions 

 which cannot be preserved by written words; and he 

 has his attention drawn to those prominent features 

 where probably he may meet with most interesting and 

 profitable geological work. First jotting >f this kind in 

 a country never before visited, and of which the geolo- 

 gical structure is still unknown to the observer, have for 

 him a special interest and value. They retain for him 

 the natural effect made on his eye and mind by the 

 scenery, apart altogether from any explanation he may 

 eventually be able to offer of the meaning of the features 

 which he impartially sketches. With increasing e 

 ence of geological structure and practice in sketching 

 it, these rapid drawings or notes gain in precision and 

 fulness. 



At first, of course, the observer may expect to meet 

 with innumerable difficulties in his traverses of a country. 

 He may find it impossible to take in any general con- 

 ception of the whole region ; everything seems lost 

 perhaps in endless multiplicity of detail. Hut as he 

 masters the detail, his power of grasping, at an early 

 period in the examination of a district, the salient 

 features of the geology, will steadily increase. In ] (ar- 

 ticular, he will be gratified to discover that he can, with 

 growing success, identify rocks and formations even from 

 a distance by their outlines, colour, character of vegeta- 

 tion, or other distinctive trait. His first surmises regard- 

 ing the geological structure of the ground, made during 

 his preliminary excursions, will thus come to be more 

 and more sustained by his subsequent surveys. In later 



