496 Theory of the Origin of Mountain- Ranges. 



support provides any lateral movement other than that due to 

 intrusions of molten rock. 



Prof. Hutton, in his description of my theory, doubtless 

 given in the greatest good faith, leaves out what are in my 

 view some of its vital and essential portions. I gave as an 

 illustration the cubical expansion of an area of rock 500 x 

 500 x 20 miles, and showed that it would, if raised 1000° 

 Fahr., have an effective increase of bulk of 52,135 cubic 

 miles *. Prof. Hutton seems to assume that this is the Alpha 

 and Omega of my theory — the beginning and the end. I 

 cannot but think it strange that he should take this view, as 

 one of the first chapters f details illustrative experiments to 

 give the reader the first conception of recurrent expansion. 



The fact is, that there is no limit to the lateral movement 

 provided by recurrent expansion, excepting the natural limit 

 of the number and intensity of the successive changes of 

 temperature. 



I can assure Prof. Hutton that if I had advanced no further 

 than the single constructive conception of cubical expansion 

 as an agent in Mountain-Building, in itself original — or, at all 

 events, not contained in the Herschel, Babbage, Scrope, or 

 Lyell conceptions of the effects of expansion on the Earth's 

 crust — the ' Origin of Mountain-Ranges ' would never have 

 been written. 



Conclusion. 



The object of this Outline being to correct some prevalent 

 misconceptions of my views, I have confined myself prin- 

 cipally to restating in a shorter form the essential principles 

 of my theory of mountain-formation by sedimentary loading 

 and cumulative recurrent expansion. For all the details, 

 proofs, illustrations, and numerical calculations I must, as 

 before stated, refer those interested to the original work. 

 Perhaps it may lead some who have already read the ' Origin 

 of Mountain-Ranges ' to again read and reconsider it, when I 

 trust the points I have touched on in this outline will add to 

 its lucidity. Honest criticism, even if severe, is one means of 

 elucidating the truth, and I not only invite but welcome it. 



Park Corner, Blundellsands, 

 Liverpool. 



* ' Origin of Mountain-Ranges/ p. 116. 

 t Ibid. Chap. III. 



