36 Anniversary Address of the 



aground or in motion, unless he had opportunities of com- 

 paring their relative position from day to day. So large is 

 the volume of ice submerged beneath the water, that the 

 waves and swell of the Atlantic during a storm have no 

 more power to communicate a rocking motion to one of them 

 than if^they were islands, or parts of the firm land. 



Should geologists ever be convinced that some of the most 

 gigantic curvatures of Alpine strata have been the result of 

 intense pressure, so moderated in its application as to have 

 been just suf&cient to overcome the resistance opposed to 

 it, — should any of them ever declare their belief that the 

 motion had been as insensible as the unfolding of the petals 

 of a flower, — it would not imply a more remarkable revolu- 

 tion in popular opinion than we have witnessed in reference 

 to the glacial hypothesis. Nor even then might we be 

 entitled to pronounce the process a slow one relatively to 

 other natural operations, organic and inorganic, which were 

 simultaneously in progress. In the fourth volume of our 

 Quarterly Journal (p. 70), Mr Hopkins, to whom you have 

 this year awarded the Wollaston Medal, has published an 

 excellent paper on the elevation and denudation of the Lake 

 district of Cumberland and Westmoreland. He has under- 

 taken, and, as it appears to me, with no small success, the 

 very difficult task of restoring, in a series of diagrams, the 

 successive steps by which the physical geography of the 

 country attained its present condition, although the changes 

 to be accounted for, consisting of the addition of several new 

 sedimentary formations, and repeated alterations of level, 

 and denudation of rocks, were numerous and complicated. 

 In one part of his memoir he has suggested the possibility 

 of the period during which the dispersion of erratic blocks 

 took place, having extended far back in ''geological time, 

 even as far as the oolitic period; an opinion which is, I 

 think, at variance with a great weight of evidence derived 

 from the study of the boulder formation both in Europe and 

 North America. But in regard to the mode of transport, 

 Mr Hopkins has taught us, that if the bed of the sea were 

 suddenly uplifted from 100 to 200 feet in vertical height, 

 such an instantaneous upward movement would give rise to 

 currents having a velocity of twenty-five to thirty miles an 



