The Interior of the Earth 



abysses and elevated into enormous mountains. 

 If, however, we reduce all these dimensions to the 

 scale of a globe three feet in diameter, mountains 

 and abysses appear to us as imperceptible 

 wrinkles, as shallow furrows at most rtrth of an 

 inch deep or high. They are all mere surface 

 accidents. The general form remains obvious; 

 it is still a sphere, slightly flattened at the 

 extremities of its polar axis. The equatorial 

 diameter exceeds the polar diameter by about fth 

 of an inch. 



Thus, notwithstanding the erosion of the 

 waters and the dislocations produced by sub- 

 terranean convulsions, the earth has not been 

 altered to such an extent that one cannot 

 recognise its primitive shape, and even if our 

 globe were actually solid to the core it must 

 have been fluid in the past in order to have 

 assumed this form. 



Another equally conclusive proof is based 

 on the distribution of densities within the 

 globe. We all know the law of universal gravita- 

 tion which it was Newton's glory to derive from 

 the laws of planetary motion, formulated by 



Kepler. It teaches us that between any two 



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