of Southern India. 



371 



for two centuries at least been found in a rock, generally sup- 

 posed to owe its origin to deposition from water, the applica- 

 tion will of course be limited to the case of diamonds found 

 in alluvial soil. 



A considerable range of mountains called the Nalla Malla * 

 (Blue Mountains?) lies between the 77° and 80° of east lon- 

 gitude. Their highest points are situated between Cummum, 

 in the Cuddapah district, and Amrabad, a town in the pro- 

 vince of Hyderabad north of the Kistna, and vary in height 

 from 2000 to 3500 feet above the level of the sea. The fol- 

 lowing barometrical f heights are taken from my own obser- 

 vations, the others are from trigonometrical calculations with 

 which I have been favoured by Colonel Lambton. 



| Trigonometrical 



Barometrical 



1 



heights 



heights 





1 above the level 



above the level 





of the sea. 



of the sea. 





3086 feet 



3060 feet 



Durgapah-condah, a hill station of 

 Colonel Lambton. 





1767 



Pass between Cummum andNandial. 





1563 



Temple of Sri Sailam±. 





2520 



Ruined Temples and StoneTank S.E. 

 of Sri Sailam, 5 miles. 



3149 



not visited 



Byramcondah, bill station of Colonel 

 Lambton. 



3055 



not visited 



Cundah-Brahmeswar, hill station of 

 Colonel Lambton. 





717 



Town of Nandial. 





• 507 



Town of Cuddapah. 





1000 



Bed of the Kistna at Moorcondah. 



The outline of these mountains is flat and rounded, very 

 rarely peaked ; and as they run N.E. and S. W. the ranges 



* I have reason to believe that this name is merely local. 



f The barometer is a late contrivance of Sir Harry Englefield. It is 

 called the Box Barometer, and is refilled at every station with purified mer- 

 cury. The cistern is of box-wood and open ; with a gauge an exact inch 

 in height, which is adjusted by a lens at the time of observation. It differs 

 but in a trifling degree from other barometers with which it has been com- 

 pared, and I believe that its horary variations are more uniform. From 

 the close correspondence usually observed between the trigonometrical and 

 barometrical heights at many of Colonel Lambton's stations, I think the 

 maximum of error is not more than 50 feet. 



J Pagoda of Perwuttum described by Col. Mackenzie in the Asiatic Re- 

 searches, vol. v. 



3 A 2 gradually 



