540 BEV. R. B. WATSON ON THE GREAT DRIFT-BEDS WITH SHELLS 



warmer summer, buried them, or a series of wetter and colder years swelled the 

 mass of ice so that it rested again with its full weight on the bank, crushing 

 down its surface, and, as it ground its way over the resisting mass, producing 

 those "striated pavements" which are well knoAvn as one of the striking features 

 of the boulder-clay. 



5. The boulder-clay contains beds which seem to have been formed on the land. 

 Such beds as those I have described at pages 528, 531. and 533 certainly give the 

 impression of their having had a glacier lying directly upon them, and the nature 

 of the position in which they lie confirms the impression of their having been 

 thrust into an angle of the strata by the glacier. But whether it be true, as I 

 believe, for these cases or not, it is obvious that instances of the kind must have 

 occurred, and are to be looked for in all such corners, and other places of the 

 basement rock, as could give shelter. 



6. The boulder-clay was deposited as the land was subsiding. Of this fact, 

 the proof which appeals to our senses is the sequence of thebeds. From thesea- 

 level to 1200 feet they can be followed uninterruptedly, with quite enough of 

 stratification to leave no doubt that the beds higher above the sea are also higher 

 stratigraphically, and rest on those below. The other proof, though not so direct, 

 rests on even a broader and less fallible basis of fact. The mere presence of the 

 boulder-clay, from the sea-line up to the mountains, implies its deposition during 

 the subsidence of the land ; for let us suppose the contrary, and imagine that at 

 some period of the glacial epoch the land previously submerged began to rise. 

 As each zone of the land successively came to the surface it would be subjected 

 to the ice and glaciated. So long as the glaciation went on, every particle of soil 

 would be stripped off" the rock and accumulated at the sea-line ; and when the 

 glacial period passed away, it would have left our land like a bleached and 

 ghastly skull projecting from the grave. 



This obviously is not the case. The whole country more or less, except only 

 the higher mountains, is covered with soil, the boulder-clay itself rising to 1100 

 or 1200 feet at least; and this is exactly what would occur under the other 

 supposition, that the glaciation of the country, and the deposition of the boulder- 

 clay, went on as the land was subsiding ; for thus, as Hugh Miller has some- 

 where shown long ago, the sea would protect the boulder-clay from the ice, 

 while the ice-foot would shelter it from the surf, and only when the ice was 

 gone would the higher level beds be so far wave-beaten and eroded as to supply 

 a coating of soil to the bare rock of the hill tops, and the higher mountain 

 summits alone would be left in the nakedness of broken and weathered rock 

 which characterises them. And here, if adaptation of means to an end be a 

 proof of design, we have a marked evidence of the work of God preparing the 

 earth for man's habitation. 



7. The subsidence extended from the present sea-level, and ultimately reached 



