24 ME. T. r. JAMIESON SUPPLEMENTAEY 



nor about Tom-na-fersit or Inverlaire, neither did I remark them 

 along the road to Bridge of Eoy much beyond the western boundary 

 of the parent rock. There are plenty, however, along the foot of the 

 hill on the east side of the Rough Burn, called on the Ordnance 

 map * Meal Clachach,' which means ' the Hill of Stones/ How 

 far up the hill they go I am unable to say, for I did not ascend it ; 

 but along its base there are some splendid examples of erratic blocks, 

 and they continued beyond the boundary of the syenite as far as I 

 went. Looking eastward over the moor on the south side of the 

 Spean it is seen to be covered with them in thousands, as far away 

 as the eye can discern such objects. 



It would seem therefore that the fragments of this syenite have 

 been carried towards the north-east, north, and north-west. Many 

 of them must have been lifted far above their original bed, and 

 altogether the display of glacial action here is one of the most 

 interesting and remarkable that I know. It is strange that the 

 mountains along the Eough Burn are nearly as lofty as those in 

 Glen Treig, and yet their territory appears to have been completely 

 invaded by the glaciers of the latter region. A glacier descending 

 the Rough Burn would have carried the moraines and boulders in 

 an exactly opposite direction. 



Here again we see that the ice from the region of greatest pre- 

 cipitation has overwhelmed that of the drier region. Although the 

 facts in this Lochaber district are so very strange and paradoxical, 

 yet there is a certain harmony in them all. For whether we look 

 to the glaciation of the rocks, the barring of the lakes, or the trans- 

 port of boulders, everything points to the same explanation, namely, 

 an excessive thickness of ice in what is now the region of heaviest 

 rainfall. 



APPEj^DIX. 



1. Prestwich's MemarJcs on the Deltas, 



Prof. Prestwich, in his memoir on Glen Eoy, disputes the nature 

 of the so-called deltas, and would explain them to be accumulations 

 of moraine detritus remodelled on the surface by water-action. In 

 particular he criticizes in considerable detail the large bank at the 

 mouth of Glen Turret. The base of this he represents to be " a 

 mass of unstratified light grey sandy clay, from 50 to 80 feet thick, 

 full of angular fragments, including a few large blocks, of the local 

 rocks." ' 



This does not quite agree with my observations. The following 

 is an extract from ray notes on the subject made at the time : — 

 " The base of this bank, as far as I could make out (for it is not 

 very clearly sectioned), is chiefly of laminated silt, rather sandy and 

 somewhat rough owing to a considerable mixture of small stony 

 debris. Above this there is a broad band of very coarse stony 



1 Phil. Trans. Eoy. See. for 1879 vol. clxx. p. 673. 



