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HUTTONIAN THEORY. 



397 



might be mod eafily done, by cutting off a part 

 from one fide, or blowing it away by giin- 



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owaer 



; the ftone would then lofe its balance, 

 would tumble from its pedeital, and might roll 

 to a confiderable diftance. Now, what art is 

 here fuppofed to perform, nature herfelf in time 

 will probably effect. If the vvafte on one fide 

 of this great mafs ftiall excee'd that on the op- 



pofite in more than a certain proportion, and it 

 is not likely that that proportion will be always 

 maintained, the equilibrium of the Logan ftone 

 will be fubverted, never to return. 



\ 



Thus 



we 



perceive how motion may be produced by the 

 combined adion of the decompofition and gra- 

 vitation of large mafTes of rock. 



355. Befides the gradual wafle to which flones 

 expofed to the atmofphere are necefluirily fubjed:, 

 thofe of a great fize appear to be liable to fplit- 

 ting, and dividing into large portions, no doubt 

 from their weight. This may be obferved in 

 almoft all flones that happen to be in fuch cir- 

 cumftances as we are now coniidering ; and from 

 this caufe the fubverfion of their balance may 

 be more fudden, and of greater amount, than 

 could be expeded from their gradual decay. 



Thus, if to the wafting of a ftone at the bot- 



tom 



dd the 



dents that may befal 



the wafting of its fides, we fee at leaft the phy- 

 fjcal poflibility of detached ftones being put in 



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motion. 



