Geological Changes in the South of Scotland. 37 



from. Of course they have all taken the same direction, but 

 those alluded to retain angles so sharp as to forbid all idea of 

 their having been rolled. Besides, such are frequently perched 

 upon situations quite adverse to the rolling theory : we some- 

 times meet with such amongst the round boulders upon the 

 surface, and not unfrequently in the boulder clay, so very flat 

 and angular, that they must have been borne there by a very 

 different conveyance from the others. We need not dwell 

 upon this part of the subject which has been so frequently 

 treated upon by far abler writers, we shall therefore pass on 

 with pointing to one remarkable instance. There is a large 

 angular fragment of green-stone seemingly upwards of ten 

 tons in weight, close by the side of the old road to Jedburgh, 

 and about a mile south from the Teviot. Upon comparing 

 specimens we find that it must have come from Ruberslaw, a 

 high hill about seven miles direct west. The deep valley of 

 the Rule intervenes, besides a considerable extent of rising 

 ground, so that the stone must have been floated over and 

 dropt upon the spot it now occupies. It is in two pieces which 

 are separate a few inches : that fracture possibly took place 

 when it fell upon the ground ; certainly it has not been broken 

 recently, and not likely ever by the hand of man. 



We now come to the last, but certainly not the least, inter- 

 esting feature in the district, that is, the mounds or moraines of 

 gravel which from time to time have elicited so much specu- 

 lation, but which have until of late as it were mocked all at- 

 tempts to account for their formation. The honour of having 

 first interpreted their true character is due to M. Agassiz, the 

 celebrated Swiss philosopher, whose experienced eye soon de- 

 tected them upon his memorable visit to this country. Those 

 mounds stand out in bold relief, often in a tortuous steep ridge- 

 like form, which, together with the local situations where we 

 find them, at once testify that they have been thrown up by 

 a very different cause from any which have yet been alluded 

 to. They are totally distinct from the debris which have been 

 swept into the rear of the hills by the combined action of water 

 currents and floating icebergs. The latter is commonly a broad 

 undulating mass, sloping to the east of the rocky heights ; or 

 behind a conical hill it takes the form of a flattish rounded 

 ridge, denominated the tail of the crag, which is often flanked 

 with gravel in low swelling undulations. But those mounds 

 now under consideration are frequently as narrow, high and 

 steep as the loose material composing them will admit of. 

 We cannot suppose water to have thrown up those mounds 

 into such a sharp ridge, so equal in breadth,, so tortuous in 

 their course, and of such a length as some of them are. More- 



