42 KEV. G. R. HALL ON 



too, in one direction only, parallel with the valley itself. One of 

 the best sites for observing this is in the neighbourhood of the 

 last great barrier through vsrhich the ice-bergs must have forced 

 their way, that is, near "Wall village. The Rev. W. Greenwell, 

 in his address in 1863,* as President of our Society, remarks — 

 "In a cutting, through which the railway is carried, were seen 

 instructive sections of the glacial drift ; and many specimens of 

 polished and striated pieces of limestone were observed in the 

 clay of which the drift consists, showing unmistakable evidence 

 of their having been set, so to speak, in ice, and subjected whilst 

 so imbedded to a lengthened course of attrition, which had given 

 them almost the polish of glass, and then scored deep lines on 

 the j)olished surface."! 



Seeing, then, that the same natural agencies have been at 

 work here as elsewhere, to which the most experienced geolo- 

 gists have attributed the formation of terraced slopes (as at 

 Glen Roy and in the Val di Noto, in Sicily), it would be too 

 much to presume to say that no portion of these parallel ridges 

 in North Tynedale is owing to natural forces, — fully competent, 

 as we have perceived them to be, to produce such phenomena. 

 My own opinion is that, so to say, the framework of some of the 

 terrace-lines probably originated in the denuding operation of 

 water, and the abrading action of the glacial currents ; but that 

 man afterwards, when ages had elapsed, came upon the scene, 

 and made these rude escarpments of nature's work subserve his 

 own purpose, by altering and adapting them, and, it may be, 

 forming others after their pattern, but better fitted for the pre- 

 cise object he had in view, on the same or similar sites. 



AetificlUu Origin. — Some observers (and I could mention 

 more than one excellent geologist, among them, for example, 

 Mr. G. Tate, F.G.S., Secretary of the Berwickshire Naturalists' 

 Field Club, as to those near Heathpool, before referred to) have 

 given it as their firm belief that to man's handiwork alone should 



♦"Transactions," Vol. IV., p. 12. 



t Similar traces of glacial action in a limestone boulder were lately noticed by Mr. Green- 

 well and the writer in the railway cutting under the Buteland ridge. 



