604 DE. J. E. MAEE AND ME. TV. G. FEAENSIDES OJf [Nov. 1909, 



of both these tributaries and of another on the north, Swere Gill, is 

 now into Cautley Beck. On the east side of Great Dummacks is 

 the most marked rocky cornbe in the Howgill Fell tract, backed by 

 Cautley Crags. The combe faces eastwards, but a large semi- 

 circular recess at its southern end faces northwards, that is, in the 

 direction of the beheaded Bowderdale. The stream from the west 

 side of Great Dummacks, called Red Gill Beck, flows for a mile 

 towards Bowderdale in a well-graded valley, the grade of which 

 is continuous with that of Bowderdale. Shortly above Cautley 

 Spout, however, it enters a gorge, and in the distance of about a 

 sixth of a mile plunges in a series of continuous cascades down 

 600 feet of vertical height, forming the Spout or waterfall at the 

 northern end of Cautley Crags. 



The eastern wall of the southern recess of Cautley Crags is con- 

 tinued as a rocky spur, becoming truncated when 300 feet above the 

 valley-bottom ; and a corresponding truncated spur topped by a 

 landslip occurs opposite on Yarlside, at a similar height. 



This arrangement points to a former ridge right across the 

 Cautley Valley, separating it from the former head of Bowderdale. 

 This ridge must have been sawn through in pre-Glacial times, or 

 in very early Glacial times : if in the latter, possibly as the result 

 of a marginal Glacial overflow. The old spurs of this ridge have 

 subsequently been truncated by the ice, which accumulated in the 

 former head of Bowderdale : this has produced the great combe 

 by glacial erosion. The ice has left a number of parallel moraine- 

 mounds on the valley -bottom below the truncated spurs, extending 

 for about half a mile down stream ; and there is a shelf in the 

 combe above the 1250-foot contour-line with terminal moraine upon 

 it, left when the ice had shrunk to a corrie-glacier. 



Red Gill Beck, before its plunge down Cautley Spout, has a wide 

 valley ; but the gentle slope on the south is cut away at the ridge by 

 the rocky precipice of Cautley Crags. It is obvious to the observer 

 on the spot that the recession of the combe by ice-erosion (with 

 the accompanying landslip and frost-work above) has cut away the 

 side of the valley nearer and nearer to the stream as it flowed north- 

 westwards, until at last the whole of the side was removed, and 

 the post-Glacial stream compelled to plunge down Cautley Spout, 

 which it has carved into a waterworn gorge showing no trace of 

 glaciation. Subsequently to this, the capture of Swere Gill has 

 occurred. High Green Gill still drains into Bowderdale, but has 

 built a delta almost to the col-level. This delta will soon become 

 a ' eorrom,' and will divert High Green Gill into Cautley Gill. The 

 changes which have here occurred recall those of Carling Gill and 

 Uldale Gill, although there are considerable differences in detail. 



We now approach a tract of country, complex alike in the 

 character of its river-captures and in its glaciation. It is drained 

 on the south side by Backside Beck, Wandale Beck, and Sally Beck, 

 the last-named here forming the boundary of the Howgill Fells and 

 running practically along the Dent Fault. 



