98 Notes on Geological Specimens from [Feb. 



At page 70, volume ii. of the Gleanings in Science, a desire is 

 expressed by a gentleman at home, stated to be of high scientific 

 acquirements, that specimens should be collected from the face of the 

 hill of Beirwarah, where it has been cut through by the Kistnah 

 river ; and the author of the queries seems to be impressed with a 

 belief, that a lake had formerly existed some way above it, towards 

 Warapilly. The distance, however, between the Warapilly ghat and 

 Beirwarah, is considerable ; and I do not think, that there are any 

 decided appearances at the former of the blue limestone of the clay- 

 slate formation* having constituted the margin of a lake. The strata 

 at the upper part of the rising ground to the north of the river are as 

 hard as those lower in the valley, or on the opposite bank. A specimen 

 of this rock, of a pure white color, and of great hardness, which I broke 

 from the summit of the ascent above Warapilly, well known to travel- 

 lers from the difficulty of riding over the large smooth slabs of marble, 

 and which would have been admirably adapted for lithographic purposes, 

 had it been free from minute crystals of quartz, was sent to you about 

 three years ago by Captain Smith of the Madras Engineers. The 

 junction of this rock with the granite to the north, could not be 

 seen, the country being flat, and covered with low jungle. Jaspers and 

 fragments of trap are found in the bed of the river, and the granite to 

 the north is intersected by numerous dykes of greenstone, usually run- 

 ning from S. E. by E. to N. W. by W. To the south of the river, 

 the country is lower, and for some way beyond the town of Dachapilly, 

 the limestone, usually dipping slightly to the south, continues to be 

 the surface rock ; which, whenever I have met with it, on the Kistnah, 

 at Cuddapah, near Auk, and the diamond mines of Banganapilly, and 

 at Tarputri in Bellary, or in the neighbourhood of the Wurdah, affords 

 the best indications of success to experiments in boring ; copious springs 

 spontaneously rising from it, or being lost in the interstices between 

 its nearly horizontal strata. 



At Beirwarah, the river Kistnah appears to have cut a channel 

 through the short ridge of hills, which terminates on either side in 

 rather precipitous cliffs, and admits the stream into the great alluvial 

 plains extending to the mouths of the Kistnah and Godavery. Above, 

 the country has much the appearance of having once been an exten- 

 sive lake, the bottom of which now forms the rich plain extending to 

 Condapilly to the N. W., and Munglegherry to the south of the river. It 



* I use this term of Dr. Voysey, but think its adoption more objectionable 

 than argillaceous limestone, used by Colonel Cullen in the Madras Transac- 

 tions. It would be better to characterise it as " blue limestone," " Cuddapah 

 limestone," or other term involving no opinion as to its geological relations. 



