I907.] AND MOUNTAIN FORMATION. 381 



centuries to bring out this complex development for all the principal 

 regions of the globe. 



11. Causes other than the Secular Leakage of the Ocean 



Bottom. 



§ 9. The presence of mountain forming processes in the sea, 

 and the absence of such disturbances in the interior of continents 

 excludes the consideration of secular cooling as an active cause 

 in the modification of the earth's crust. — In the paper on the tem- 

 perature of the earth we have seen that secular cooling is a very 

 slow and gradual process; and, moreover, it would necessarily 

 operate as effectively for inland as along the sea coasts. Conse- 

 quently if this cause were real, it ought to produce effects inland 

 comparable to those along the edges of the continents; but the 

 mountains are forming in the sea, and those already completed are 

 distributed along the sea coasts; so that no one would think of 

 ranges now being developed in an interior region far from the 

 oceans. The absence of such mountain-forming processes in the 

 interior of the continents therefore excludes secular cooling as an 

 active agency in the modification of the earth's crust. The effects 

 of secular cooling could in no case exceed the disturbances noticed 

 in the inland regions, aud as these are insensible in regions free from 

 water, it follozvs that secular cooling is not a true physical cause of 

 mountain formation and kindred phenomena. Consequently this 

 cause is not nozv and never has been active in modifying the crust 

 of our globe. 



§ 10. The Untenability of the Theory that World-Shaking Earth- 

 quakes Arise from the Snapping and Bending of Rocks. — In view 

 of what has been established in this series of papers, it is difficult 

 to see how any one could again ascribe world-shaking earthquakes 

 to the bending and snapping of rocks under stresses arising from 

 the progress of secular cooling. If this is the cause which is at 

 work, why should the great seismic disturbances occur chiefly in 

 or near the oceans, and especially where the sea is deep, while 

 inland regions remain quiescent? By no possible stretch of the 

 imagination can these movements be traced to the secular cooling 



