PREVIOUS OBSERVERS. 9 



very considerable section of the country, to form a conclusive opinion as 

 to the gneissic age of the main mass of the rocks of which it is formed. 



, CHAPTER U. 



PREVIOUS OBSERVERS. 



But very little geological information had been collected about either 



of the two districts here described when the survey 

 Greenough's map. -n i t • i i i 



was taken up. Both districts had been represented 



in Greenough's geological map of India ; and like all the other districts 

 with regard to which the map has been tested, the representation was 

 in many ways very far from a true one. 



Long lists of rocks and minerals observed in Madura district and col- 

 lected by the Reverend Mr. Muzzy of the Madura 

 Dr. Muzzy. ... . . 



American Mission were published in the catalogue 



of the Madras Museum in 185.5. Unfortunately the lists are deficient 

 in detailed information as to the localities of occurrence of many of the 

 rarer minerals, so that they have not been traceable in the short time at 

 my command. The rock specimens too are enumerated fr jm a mineralo- 

 gist's rather than a geologist's point of view, so that practically the lists 

 are of very little use in explaining the structure of the country. 



The geological notes in Mr. Nelson's very able and interesting 



manual of the Madura District (which is unfor- 

 The District Manual. 



innately out of print) are nearly all based upon 



Mr.Muzzy's data. 



For Tinnevelly district generally even much less had been pub- 

 lished than for Madura, and it was only for the 

 Dr. Caldwell. •' 



extreme south-east corner that a short but interest- 

 ing sketch, relating chiefly to the more recent deposits occurring there, had 

 been published by the Revd. Robert Caldwell, LL.D., the eminent 

 Dravidiau scholar, now Missionary Bishop in Tinnevelly district. Dr. 



( 9 ) 



