Br HFGH MILLER. 337 



drainage of its basin, which flows away in front, into two un- 

 equal moieties, the larger of which is naturally that favoured by 

 the general slope. JN'ow between these unequal divisions the 

 crowning escarpment, with the bank below it, obtusely projects, 

 so as to make the curve of the coombe a distinctly double one, 

 which the letter B will illustrate in an exaggerated way. TJiat 

 this projection should coincide with the space hetween the tivo unequal 

 hasins can scarcely be accidental. It signifies that each drainage 

 basin has pushed back the escarpment bounding it; while be- 

 tween them, where there is less ready transport for waste, it has 

 receded more slowly. If its present glaciation represents any- 

 thing like what the coombe has suffered from the glaciers, this 

 must have happened before the ice age, and although a feature 

 which a cursory visit might overlook, it is to me a very marked 

 and significant one. Such things do not happen by chance ; and 

 a corner of drift which now lies sheltered between the curves, 

 while the streams have cleared out their hollows, clearly shows 

 that work has been resumed under the old conditions."^' 



All the facts I have been able to gather uniformly tend to 

 shew that Tynedale escarpments, when fully developed both in 

 "Crag" and ''Tail," have suffered but little from glaciation. 

 But upon the terraciform sculpturing of the low grounds it told 

 heavily. Terraces consist of little more than escarpment-fi^onts, 

 and as the fronts have been rounded over, this to the terraces 

 has often meant obliteration. 



In casting the eye from the watersheds down to the valleys, 

 therefore, we remark, that all the chances have favoured the pre- 

 servation and re-development of the sculpture on the heights, and 

 militated against these on the low grounds. On tlie heights the 

 escarpments were fully differentiated, and suffered little more 

 than a smoothing; the elevation and the comparative absence of 



* It might be inferred from tliis that this cooml)e is only a deep symmetrical tlrninage 

 basin, differing mainly from those often to be seen from a distance scooped in clam-shell- 

 form on the sides of mountains in being deeper, and in having its interior ribbed by 

 transverse ridges. There is much to bo said for this view, which struck nic— as I have 

 pleasure in admitting— in thinlting over the Rev. T. G. Bonney's theory of the formation 

 of Alpine corries by a conjunction of waterfalls. To this siil)ject I may hope to devote 

 ajiother paper. 



