354 THE CANADIAN NATURALIST. [Oct. 



blocks of stone, were floated southwards from great Scottish gla- 

 ciers which protruded into the sea. 



Coming hither in ignorance of what the several associations of 

 local geologists (which rival each other in their researches) have 

 accomplished, I shall be happy to learn that some of them have 

 detected, in this portion of the kingdom, any of those proofs of 

 the existence of man at an early period, when large animals, now 

 extinct, prevailed in our islands, in ages so remote that, since then, 

 the physical configuration of the country has undergone great 

 changes. This inference is, as I have said, founded upon irrefragable 

 evidence collected in different parts of Europe, as well as in our 

 own country. When, however, we come to consider the modus 

 operandi by which these great physical changes have been brought 

 about, geologists have different opinions. As one who holds to the 

 belief that in former periods the crust of the earth was from time 

 to time affected by an agency much more powerful than anything 

 which has been experienced in the historic era, I do not believe 

 that the wear and tear due to atmospheric subaerial erosive agency 

 could, even after operating for countless ages, have originated and 

 deepened any of the valleys and gorges "which occur in countries as 

 flat as the tract in which we are now assembled. 



But whilst I adhere to my long-cherished opinion as to the great 

 intensity of power employed in the production of dislocations of the 

 crust of the earth, and though I cannot subscribe to the doctrine 

 that the ordinary action of deep seas remote from coasts can ade- 

 quately explain the denudation of the old surface, even by invok- 

 ing any amount of time, I recognize with pleasure the ability dis- 

 played by my able associates, Ramsay, Jukes, and Geikie, in sus- 

 taining views which are to a great extent opposed to my own in 

 this department of Theoretical Geology. 



Admiring the Huttonian theory, as derived from reasoning upon 

 my native mountainous country, Scotland, and fully admitting that 

 on adequate inclines ice and water must, during long periods, have 

 produced great denudation o&the rocks, I maintain that such rea- 

 soning is quite inadequate to explain the manifest proofs of con- 

 vulsive agency which abound all over the crust of the earth, and even 

 are to be seen in many of the mines in the very tract in which we 

 are assembled. Thus, to bring such things to the mind's eye of 

 persons who are acquainted with this neighborhood, I do not ap- 

 prehend that those who have examined the tract of Coalbrook Dale 

 will contend that the deep gorge in which the Severn there flows 



