482 PKOCEEDINGS Oi' THE GEOLOGICAL SOCIETY. [June 19, 



aground again until it came to a reef of less, or at any rate equal 

 depth from the surface of the sea. 



But there is yet another position in which this effect is observed ; 

 and that is, on the north side of a hill where the dip is into the hill or 

 south (a in the diagram, fig. 2). Here the edges of the beds have 

 been pushed up hill instead of dowa, though still in the same direction. 

 This cannot in any case be referred to subaerial " drag " or " trail," 

 but exists in spite of it. Again, this might be thought the resrdt of a 

 thrust from an iceberg floating against the ridge ; but in so soft a rock 

 as shale, in which this usually though not exclusively occiu-s, it seems 

 probable that the berg in recoiling would detach the material already 

 loosened by the first forward thrust, and so tend to deface its own 

 work. Can we suppose that in this case the beds have been thrust 

 up hill by an ice-foot fringing the shore, and raised higher at every 

 tide by the accumulation of fresh ice at its base ? It seems plausible. 

 Yet, if we admit it, we shall have to allow that whereas on the 

 northern beaches of narrow islets the ice-foot was forcing the edges 

 of the beds upwards and inland, on the southern shores it was 

 dragging them downwards beneath the sea — an hypothesis which 

 cannot be maintained for an instant. 



The question then comes to this. Shall we attribute the same 

 eff"ect at a (in the diagram, fio-. 2) to an ice-foot, at b to icebergs, 

 and at c to subaerial " drag?" or shall we recognize at both a and 

 B the effects of icebergs, and at c the work of subaerial agents ? for 

 no one of these is in itself sufficient to account for all three cases. 

 Such explanations, taking all the facts together, would seem, to say 

 the least of it, to be rather forced and unnatural. 



On the other hand, if we can find an agent which will consistently 

 account for this identical effect in all the positions in which it occurs, 

 and also give a solution to several other groups of kindred facts 

 which cannot be readily explained in other ways, we should accept 

 it without hesitation. And such an agent is the great ice-sheet 

 pushing on from its northern gathering-grounds, recruited by the 

 greater elevations on its course, but overriding the lesser, grinding 

 down and smoothing by its weight and friction rocks presenting but 

 a gentle incline, tearing up and turning over the basset edges con- 

 fronting its approach. For, be it noted, it is only on the southern 

 side of- the anticlinal, where the outcrops face the north, that these 

 appearances are to be found ; throughout the whole of the northern 

 part of the district, all about the Central Pells, where the beds are 

 dipping north or lying at gentle inclines, nothing of the sort is to 

 be seen. The reason is clear. Where the beds dip north they suc- 

 ceed each other in relation to any force coming from the north, as 

 do the tiles of a roof to the rain ; but where dipping south the 

 arrangement is just the reverse. To use a homely illustration, in 

 one case the brushing was with the nap, in the other against it. 

 These superficial movements are common, so far as I have seen, all 

 along the Pendle range. I have seen them some distance south-west 

 of Blackburn. Between the Calder and Pendle HUl, more particularly 

 about Padiham Heights, they are very frequent. Mr. Hull and 

 I, in surveying this ground, found them in nearly every quarry-, 



