198 



NATUEE FOE ITS OWN SAKE 



The earth's 

 surface. 



Inequalities 

 of surface. 



like, and if we could see it from a distance 

 denuded of atmosphere, it would doubtless 

 appear as a ball of water with patches of land 

 like large islands projecting above the surface. 

 The greater part of the surface is on one level 

 that is to say, sea-level, which we accept as the 

 standard. Above it there are elevations of 

 land in points and ridges called mountains 

 projecting upward some thirty thousand feet ; 

 and below it there are depressions or holes in 

 the sea extending down some thirty thousand 

 feet. There are numerous exceptions to the 

 rule of the sea-level marking land above and 

 water below. Some of the plains and basins 

 are below or above the sea-line. The margin 

 of the Dead Sea lies thirteen hundred feet 

 lower than that of the Mediterranean, and the 

 great lake of Titicaca in the Andes, with an 

 area of three thousand square miles, is nearly 

 thirteen thousand feet above the Pacific. From 

 Titicaca downward there are hundreds of 

 bodies of fresh water conserved in great basins 

 of the earth, which are as upland reservoirs to 

 the sea itself. 



It is fortunate, indeed, that the earth has 

 these upland reservoirs, fortunate that they 

 are so equally distributed over the face of the 



