of Southern India. 373 



their summits of sandstone and quartz rock ; the basis or re- 

 maining two-thirds being of granite *. 



This range of mountains is intersected by the rivers Kistna 

 and Pennar, and both appear to pass through gaps or fissures 

 in it, which have been produced by some great convulsion, 

 which at the same time that it formed the beds of these rivers 

 gave passage to the accumulated waters of some vast lakes si- 

 tuated near the outlets. 



The tortuous passage of the Kistna for upwards of seventy 

 miles is bounded by lofty and precipitous banks, which in 

 some places rise to 1000 feet above its bed : the opposite sides 

 of the chasm corresponding in an exact manner. Ravines of 

 this description are not unfrequent all over the range, and the 

 exact correspondence of their opposite salient and re-entering 

 angles, together with the abruptness of their origin, totally 

 preclude the supposition of their being hollowed out by the 

 action of running water. 



Two of these remarkable chasms occur on the western road 

 to the shrine of Maha Deo at Sri Sailam, and would be to- 

 tally impassable to travellers, but for the more magnificent 

 causeway and steps, which wind down the precipice. 



The only rock of this formation in which the diamond is 

 found is the sandstone breccia. I have as yet only visited the 

 rock mines of Banganpalli, a village situated about twelve 

 miles west of the town of Nandiala. The low range of hills 

 in which these mines are situated appear distinct from the 

 main range, but a junction of the north and south extremities 

 may be traced with great facility. 



The breccia is here found under a compact sandstone rock, 

 differing in no respect from that which is found in other parts 

 of the main range. It is composed of a beautiful mixture of 

 red and yellow jasper, quartz, chalcedony and hornstone ol 

 various colours, cemented together by a quartz paste. It 

 passes into a puddingstone composed of rounded pebbles of 

 quartz hornstone, &c. cemented by an argillo-calcareous earth, 

 of a loose friable texture, in which the diamonds are most fre- 

 quently found. 



Some writers have miscalled this rock amygdaloid or 



* I have reason to believe, partly from personal observation, and from 

 specimens obtained from other sources, that the basis of the whole penin- 

 sula is of granite. 



I have traced it along the coast of Coromandel lying under laterite (Bu- 

 chanan's name for the iron-clay of Jamieson) from Pondicherry to Masuli- 

 patam. 



From Rajahmundry to Nandair in the bed of the Godavery. 



And I have specimens from the base of the Seetabaldi hills, Nagpoor. 

 From Travancore, Tinnevelly, Salem and Bellary. 



wacken. 



