Earth's Axis of Rotation. 103 



see that, as soon as this is effected, it is attacked along the sea- level 

 by the breakers, and both on coasts and inland by atmospheric in- 

 fluences, all tending to lower the altitude of the mass so elevated, 

 and to carry its component parts into the sea, filling up any inequalities 

 which may have been formed beneath it, in consequence of this 

 surface-movement of the rocks. It is during this removal of mineral 

 matter and its spread in various directions, that the remains of the 

 animal and vegetable life of succeeding geological times become 

 entombed, adding, and in many instances most materially, to the 

 masses accumulated in various ways upon the previously moved rocks. 

 This action, therefore, tends to plane down the unequal surface above 

 the sea and fill up inequalities in its bed. While this pi'oceeded, 

 we should expect that the heated matter beneath would also melt 

 down any portions of the solid masses, squeezed and forced into it 

 by these movements, to a distance from the surface corresponding 

 with the general heat of the globe at the time, and therefore the 

 deeper as geological time advanced and the earth gradually parted 

 with its heat, by radiation, into surrounding space. 



Under this view there would be a tendency over the face of the 

 globe to retain a general crust upon it of a thickness increasing with 

 the lapse of geological time, less uneven beneath, as a whole, than 

 above, from the kind of action to which it would be subjected, and 

 yet no part protruding so far as to cause any very material difference 

 in the figure of the earth, or of density, in the parts of such crust. 

 Viewing the subject on the large scale, it would not appear im- 

 probable, that notwithstanding the dislocation, unequal tilting, and 

 squeezing together of masses, the adjustments were such as to keep 

 a spheroidal coating of the mass beneath, which did not vury mate- 

 rially differ as a whole in density. Should this not have been so, we 

 have in our geological hypotheses to take into account the effects 

 pointed out by Sir John Lubbock as resulting from the modification 

 or absence of the general conditions above inferred, their amount 

 or geological value necessarily depending upon the magnitude of the 

 causes to which he adverts. 



