Mr Hardy on Langleyford Vale and the Cheviots. 373 



syenites of extraneous origin, but this is owing to the peaty 

 waters having discharged the fleshy hue of the felspar. On 

 the Hedgehope side, however, at the head of the vale, there 

 is a native rock with paler felspar ; and it has given origin 

 to a great number of these pseudo-syenetic boulders, which 

 can be traced down to Wooler. The upper portion of this 

 paler variety being overlapped by peat, is called the Black 

 Crag, and it is almost the sole remnant of exposed rock now 

 left, except in gullies, on the northern slopes of Hedgehope. 

 It lies at the very head of the valley ; and from being so much 

 pared down and rounded — pared down, but not polished, — 

 it appears still to bear the impress of the movements of the 

 ancient glacier that extended up and down the valley. 



But there has been also a secondary movement of these 

 boulders, which is still being carried on. During spates, the 

 wild hill-burns dislodge and bear down all that they can 

 shift; as is apparent from the crowds strewed near their 

 courses, or accumulated at their junction with the lower 

 streams. Both on the slopes of Cheviot and Hedgehope 

 there are lengthened streams of stones irregularly scattered, 

 stretching far down the declivities, and sometimes terminat- 

 ing in quantities huddled together. It was only recently 

 that I ascertained how this came to pass. Happening to 

 cross a slip of peat which had recently precipitated itself 

 down the slope near the Black Crag, I found that along with 

 the peat, the movement had torn up and brought with it the 

 boulder rocks beneath it — for, as I mentioned, they constitute 

 a loose stratum under the turf, — and had arranged them in that 

 long straggling line, which had hitherto appeared inexplic- 

 able. Passing over to the Cheviot side and scrutinising 

 Hedgehope, I could now trace the lineaments of numerous 

 old slips, still visible on its face but now overgrown with 

 grass. The peat, which, now broken up by frequent " peat- 

 brooks," overhangs, with ragged edge, the slopes, is retro- 

 grading, and probably once extended much farther down the 

 slope, the mountain grasses having occupied the cleared 

 spaces. This gradual transition to an ameliorated condition 

 is precisely what is observable on the top of Cheviot wherever 

 the fundamental clay is bared by the removal of the peat. 

 The sheep's fescue and other grasses soon colonise the new 

 soil, and produce strips of meadow. 



The exceeding thickness of the clays in the sections ex- 

 posed by the ravines and open drains on these hills is worthy 



3b 



