OP THE earth's surface. 203 



and nearly in opposite directions ; and the analogy of the 

 events at Lisbon and at Lima, leads us to suppose that seve- 

 ral similar actions may have taken place in succession. At Lis- 

 bon, five waves in succession followed the first. In the present 

 case, the influence of all but the first, would probably be 

 confined to the western side ; or if any of the rest possessed 

 elevation sufficient to surmount the ridge, still the portion of 

 its water which passed over, and that which returned, would 

 each follow the same course with the corresponding portions 

 of the first wave. And there is every reason to believe, that 

 the action would be repeated often upon the side facing the 

 inundation. 



The facts seem to correspond with this theory. We have 

 endeavoured to account for the peculiar form of craig and tail, 

 and for the parallel ridges, so frequent on the eastern coast, by 

 the influence of a single powerful stream, the effects of which 

 have since undergone no modification, but from the feeble exer- 

 tions of diurnal causes ; whereas, on the other side of the island, 

 the same set of forms, which we may conceive to have been gene- 

 rated by the first direct impulse, being assailed in new direc- 

 tions, by other forces, less powerful, but frequently repeat- 

 ed, we have reason to expect that these assemblages, compo- 

 sed of loose, and newly deposited materials, would undergo great 

 changes, and that the ridges would be broken down into succes- 

 sions of knolls ; that the crags would be filled up, so as to equa- 

 lise the declivity on all hands ; in short, that such a scene as 

 the west coast of Scotland presents to view, would be the re- 

 sult. The circumstances of detail concur with the observa- 

 tions founded on the large features j at least they by no means 

 contradict them. In the west, many striking instances occur, 

 of rocks dressed with grooves and furrows, as already described 

 in the east : but there is this material difference between the 



C c 2 two 



