CHAPTER XI 



MOUNTAINS AND HILLS 



THE mountains have more than once been 

 characterized as the " backbone " of the globe 

 or of the continent, but one cannot think the 

 simile other than misleading. The globe has 

 no more backbone than the sun-baked bowl of 

 a Zufii Indian. It has not even a rib or a 

 vertebra; and the mountain-ridge is no more 

 its binding member than the upheaved track 

 of a mole across a garden is the band that 

 holds the garden together. The mountain- 

 ridge, however, is not produced in the same way 

 as the mole-ridge. The great layers of rock, 

 piled up on end like the poles of an Indian's 

 tepee, that make the Alpine peaks, are more the 

 result of lateral pressure than direct upheaval. 

 They were pushed up as a wrinkle in the crust 

 of the earth, and the beds of loose soil that 

 lay above the rock were rolled back into the 

 valley, leaving the ragged edges of the crust 

 exposed to view. In other words, a mountain- 

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ridg*. 



