480 peoceedijS'gs of the geolosical sociErr. [June 19, 



belong to the system which crossed over the shoulder of Pendle Hill 

 and went up the Calder valley. One scratched " roche moutonnee " 

 occurs under Mellor Beacon ; its direction is W. 13° S., one of the 

 very few instances of scratches with so much of west and so little of 

 south in them, and its direction is probably due to local causes. 



The scratches along the coast are not many, the greater part being 

 well covered with drift ; but those which do occur seem to agree well 

 in their direction, giving one the idea of a great ice-stream coming 

 to the S.S.E. from the Lake-district, and so damming up the whole 

 of the ice-drainage of the district as to compel it to work across 

 the hills and valleys towards the south, instead of between and along 

 them to the south-west. 



The diagram (fig. 1) gives a summary of the ice-scratches observed, 

 reduced to a common centre. The radii show by their thickness the 

 proportional frequency of ice-scratches in each direction ; and the 

 numbers are appended. It is a fact worthy of note that 20 per cent. 

 of the whole are running due south. 



II. Other Indications oe Ice-movement. 



I will now proceed to describe other appearances on the siirface of 

 the rocks which seem to point to the passage of ice over them. 



The range of the Pendle chain which runs from near Chorley on 

 the western plain to Skipton forms the southern side of the great 

 compound anticlinal to which I have already referred as that in 

 which the Ribble valley south of the Pennine chain is excavated. Its 

 general range is E.N.E. ; and therefore its general dip will be S.S.E. 

 But this dip, for the greater part of its length, is at very high angles, 

 from 30° to 60°, and sometimes more. Along the southern flank 

 of these hills you find over wide areas the diff'erent laminte of the 

 beds at the surface so turned over in a downhill direction, i. e. 

 south, that the angle of dip is either considerably increased, or even 

 reversed, to a depth of one or two feet or more (fig. 2). It is ob- 

 vious that this is not due to any internal movements of the crust ; 

 for it does not penetrate below the surface. I am aware that this 

 phenomenon has been before noticed, and often referred to a sub- 

 aerial "drag" or "trail" of soft beds to a lower level by reason 

 of gravitation under the softening and loosening influences of rain 

 and frost ; but we also get it on the tops of the hills as well as on 

 the slopes, and here gravity would have very little or no field for 

 action. In this position it has been referred to the agency of 

 icebergs grounding on ridges of rock and thrusting the projecting 

 edges of the beds over by the shock. Granting that this is pos- 

 sible, we must yet allow that if an iceberg floating from the north 

 grounded on the top of a ridge, the very fact of its so doing 

 would prevent its exerting this power on the southern flank, which 

 would be in deeper water, and so protected from the abrading 

 power of any floating body of eufiiciently light draft to pass over 

 the top of the ridge without hindrance. And any iceberg ground- 

 ing on the ridge would have to be reduced in bulk by melting, or 

 by breaking itself upon the rock before passing, and would not run 



