116 WALKS AND TALKS. 



But now, in settling down, its circumference must con- 

 stantly become less. How can its circumference be made less ? 

 Only by squeezing together from all directions. There must 

 be a lateral pressure experienced at every point. It arises 

 from the weight of the crust, and is proportional to the weight 

 of the crust. If the crust is thus subjected everywhere to an 

 enormous lateral pressure, then, either the parts of the crust must 

 be mashed together, producing a thickening in proportion to dimi- 

 nution of circumference ; or else, if the crust is too solid to be 

 crushed, it will wrinkle just as the skin of an apple is wrinkled, 

 when the pulp within shrinks through the evaporation of juice. 



Now, suppose that stage of things has been reached. Some 

 wrinkles have made their appearance on the surface of the 

 earth. They are the beginnings of mountains. If ocean 

 waters rest now on the earth's surface, they may, indeed, totally 

 cover these wrinkles but they are the germs of mountains, 

 nevertheless. As long as the earth's interior continues to lose 

 heat and contract, so long wrinkling tendencies will exist. 

 But, after a set of wrinkles has been first developed, the 

 wrinkling tendency afterward finds relief in the same 

 wrinkles in the enlargement of the first wrinkles. The power 

 to enlarge and further elevate the old wrinkles will be attained 

 before the power to initiate wrinkles in new places. In this 

 way, the germinal mountains would grow. In this way, the 

 first uplifted masses would afterward be uplifted higher, as 

 new relief had to be sought. Did we not observe the succes- 

 sive stages of uplift in our study of the Adirondacks ? 



There is no volcanic uplifting here. It is true, however, 

 we may get volcanic phenomena. The crust presses with 

 enormous weight on the molten ocean. Compare it with a 

 field of ice a mile square and three feet thick, floating on a 

 lake. If you make a hole through the ice, the water rises in 

 the hole, nearly to the surface of the ice. If the hole is sud- 

 denly made, the water may rise with such velocity that its 

 momentum will carry it quite to the surface, or over the sur- 

 face. This is like an outflow of volcanic matter through a 

 fissured crust. Suppose a great number of piles of ice be 



