ON OPPOSITE SIDES OF THE PENNINE CHAIN. 189 



valleys in the neighbourhood, and the general surface-contour of the 

 surrounding district as compared with the country on the western 

 slope of the chain immediately beyond the watershed, where ice is 

 known to have been, and where the hills and dales lose their stern 

 angular character, and become characterized by a soft, rounded, and 

 flowing appearance, indicating unmistakably the operation of diver- 

 gent forces, and the existence of w r holly different conditions, we shall 

 have no difficulty in concluding that glacial or land ice has had no 

 share in their formation or subsequent modification, but that they 

 owe their origin in the first instance to the fracturing of the rocks, 

 and subsequently to the operation of subaerial forces. 



Having now pointed out the physical features of the district, I 

 shall proceed to offer some reasons for concluding that during the 

 glacial period these lines of communication were blocked up by snow 

 or ice so as to cut off all connexion between the two sides of this 

 chain of hills. On the approach of the long w T inter which preceded 

 the period when ice overspread the county of Lancaster and the 

 whole of the northern part of our island, the severity of the climate 

 would gradually increase ; and during this time large accumulations 

 of snow would take place, and ice be formed in deep and sheltered 

 situations like those presented by the AValsden, Cliviger, and Tod- 

 morden valleys. The snow, thus accumulated to a depth of from 

 80O to 1000 feet, would, by being partially melted and recongealed, 

 become in time a consolidated compact mass, little if at all inferior 

 to that of ice itself in density and consistency. 



Accepting, then, this proposition, we shall have no difficulty in con- 

 cluding that these bodies, held firmly in their places in the tortuous 

 serrated valleys which are so constructed, and holding such relations 

 to each other that any attempt to move on the part of the accumu- 

 lations in one of the arms Avould be resisted and counterbalanced 

 by the opposing force of the other two branches, each of which 

 would have a tendency to move in an opposite direction, would thus 

 be able to offer an effectual resistance to the force of the great 

 northern glacier, on its approach so far south, to dislodge them from 

 their strongly intrenched positions, — the resistance to all motion on 

 their part being still further increased by the presence of the gla- 

 ciers acting upon the terminal portions of the two arms at the 

 mouths of the valleys by which those bodies, if in motion, would 

 have to emerge, with a force equal to that exerted at the northerly 

 end of the Cliviger gorge, where the glacier would seek to effect an 

 entrance therein, thus completely neutralizing each other, and pre- 

 venting any motion on their part taking place. The progress of the 

 glacier in its journey south being thus arrested by an impassable 

 barrier, at or near Holmes Chapel, in the Cliviger gorge, where the 

 valley suddenly contracts and becomes hemmed in on both hands 

 by massive beds of grit rocks, in some places almost vertical, it 

 is evident that the ice forcing its way so far would be compelled 

 either to move on over the imbedded and stationary mass, or be de- 

 flected from its course, and compelled to take a more westerly direc- 

 tion, part of it finding its way over the pass separating the Easden 



