No. 20. [From Encyc. Brit, qth ed. 1882, Vol. xiv. p. 216.] 



LAKES 



WHEN a stream in its course meets with a depression in 

 the land it flows into it and tends to fill it up to the lip of its 

 lowest exit. Whether it succeeds in doing this or not depends 

 on the climate. In the British Islands, and in most temperate 

 and equatorial regions, the stream would fill the depression and 

 run over, and the surplus water would flow on towards the 

 sea. Such a depression, with its contents of practically stag- 

 nant water, constitutes a lake, and its water would be fresh. 

 In warm dry regions, however, such as are frequently met 

 with in tropical latitudes, it might easily happen that the 

 evaporation from the surface of the depression, supposed filled 

 with water, might be greater than the supply from the feeding 

 stream and from rain falling on its surface. The level of the 

 waters in the depression would then stand at such a height that 

 the evaporation from its surface would exactly balance the 

 supply from streams and rain. We should have as the result 

 a lake whose waters would be salt. Lakes of the first kind 

 may be considered as enlargements of rivers, those of the second 

 kind as isolated portions of the ocean; indeed, salt lakes are 

 very fn -<|u -ntly (ailed seas, as tin- Caspian Sea and the Dead Sea. 

 The occurrence of freshwater lakes and salt lakes in the same 

 drainage system is not unrnninmn. In ti the -alt lakr 



forms the termination. \\Vll-known example of this are 

 Lake Titicaca and the Desguadero in South Anuii. , ( . and 

 Tiberias and the Dead Sea on tin Jordan. 



n'hntion of 1 Although th- rmmtrirs 



re lakes are cntin 1\ al>>riit. >till it rr<|iiii< ^ liitlr >tudv t<> 



see thai tlii-v are mu< h nmrr thi klv grouped in -nine places 



rs. Of the larger lal tin- 



rk.ible group in North Ann-ri.M. whi< h together fnin 



B. III. I 



