280 



GEOLOGICAL SURVEY 



fieldwork to collect. No amount of word painting, however 

 excellently done, will convey a clear idea of an unseen lands- 

 cape, but a sketch, even though a rough one, immediately 

 conveys a distinct idea and enables the spectator to realize in 

 great measure what he vainly strove to do before. The 

 geological map is the sketch supplying the distinct idea of 

 the structure of the country and of the relative geographical 

 distribution of the mineral wealth it may happen to contain. 

 The preparation of a general geological map of a new, or 

 little known, country is therefore the second great object of a 

 geological survey, the first being of course the discovery of 

 new deposits of valuable mineral. This first object is one that 

 may be attained fully or partially, or not at all, according to 

 the peculiarity of the country traversed ; (hunting for minerals 

 will not cause them to appear where nature has not placed 

 them), but the second object is one that can always be attained 

 if sufficient time be allowed for the ground to be gone over. 



The time that should be allowed cannot be calculated closely 

 beforehand ; there are so many factors to be considered, e.g., 

 the size and accessibility of the country under survey, the com- 

 plexity or simplicity of the geological structure, the scale 

 of the survey, the amount of detail to be given, the number 

 of surveyors you can place upon the work, the length of season 

 during which fieldwork can be carried on, favorable and 

 unfavorable seasons, and last but not least, in tropical countries 

 especially, the sickness or health of the men engaged. These 

 different factors vary so exceedingly in different parts of a 

 vast country like India that it is extremely difficult to make 

 even a guess how long it will take to finish a large and 

 diversified tract of country. Many difficulties that formerly 

 beset the surveyor have been overcome by the extension of 

 railways and good roads ; while new and reliable maps and 

 the very valuable information contained in the new District 

 Manuals are also of great assistance. 



