VI PRELIMINARY NOTICE. 



tion for an extension of the line of Railway adapted to meet the 

 increasing demand for coal, and for its conveyance to market. 



The usual working season of 1858-59 had already considerably 

 advanced, when, in compliance with this desire on the part of Govern- 

 ment, Messrs. ~W. Blanford and W. L. Willson, then both engaged in 

 Birbhum, were requested, to take up the examination of this field. It 

 was my object to secure, if practicable, during that season, an examin- 

 ation of the whole of the more important part of this field. And this 

 was to a very great extent accomplished. Early in 1859, I went 

 myself over all the most productive parts of the field, and then reported 

 to the Government on the matters referred specially for my consider- 

 ation. A large portion of the district, however, was necessarily left 

 unvisited, including all lying south of the River Damtida. The examin- 

 ation of this was resumed in the next working season, 1859-60, by 

 Mr. W. Blanford alone.* He also re-visited all the other parts of the 

 field, and by the close of the working season in May 1860, he had com- 

 pleted the field-work of the entire district. During the monsoon of 

 that year, this Report and the Map were prepared ; and in the early 

 part of 1861 the entire field was re-visited by myself, and the Map 

 carefully checked. 



This is the first Map which the Geological Survey in India has 

 issued on the larger scale of 1-inch to the mile, on which scale, 

 however, all our field-work, is recorded, wherever the maps exist. It 

 would, in this case, have been impossible to have given all the detail 

 which Mr. Blanford has carefully entered on his map, on a smaller, 

 and the importance of the field would fully justify even a larger, 

 scale than this. 



This being also the first instance in which the maps of the Geolo- 

 gical Survey refer to districts of which no authorized map has yet 



* Mr. Mallet, in 1858-59, and Mr. Tween, in 1859-60, both worked with Mr. Blanford, 

 but as these gentlemen were new and untrained assistants, their aid was not of much 

 importance. 



