Ball — On some Effects Produced by Landslips. 3 



The illustrations and plans wliich I now exhibit will serve to 

 convey an idea of the principal of these Himalayan l-akes (Naini 

 Tal) and its surroundings. For descriptive details of it and the 

 others of the series I must refer to my original Paper. Here it 

 will be sufficient, perhaps, to concentrate our attention on Naini 

 Tal as typical, though some of the other lakes exhibit individual 

 peculiarities indicating local modifications in form, which may 

 possibly be connected with the irregular profiles impressed on the 

 surface of the rocks at the time of their upheaval, and which are 

 therefore less directly due to the effects of subserial denudation. 

 Though often tacitly assumed, it is not, I submit, justifiable to 

 conclude that upheavals of mountains left simply plane surfaces for 

 the subserial forces to operate on ; ridges and hollows must as- 

 suredly have been produced by such disturbances among non- 

 homogeneous rocks. 



Naini Tal occupies the bottom of a valley which runs with the 

 strike of a variety of altered rocks, among which much contorted 

 and splintered shales are the most prominent : there are also some 

 limestones, generally occurring in lenticular bands, and indications 

 of the presence of a deep-seated dyke, or dykes, of trap have also 

 been observed. 



Where the slopes are gentle the upturned edges of the shales 

 are more or less covered by humus, which in many places supports 

 good-sized oak and other trees. The ledges which are cut into this 

 humus, in order to afford sites for building, serve as collecting- 

 grounds for the drainage, and have been the principal cause of the 

 disturbance of the equilibrium, which has resulted in the landslip 

 about to be described, as well as of many previous ones known to 

 have taken place in the same locality. 



The facts connected with the Naini Tal landslip are the follow- 

 ing : — On Saturday, the 18th of September, 1880, after about 

 forty hours of continuous rainfall, during which time twenty-five 

 inches of rain fell, at 10 o'clock in the morning a slip occurred on 

 the north-east slope of the valley, which buried a portion of the 

 buildings behind the Yictoria Hotel, in which there were at the 

 time some natives and a European child.. 



By the aid of a party of volunteers and some men from the 

 military depot, all who had been buried in the ruins, and were 

 still alive were rescued; It was then observed that a stream of 



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