MR JIILNE ON THE PARALLEL ROADS OF LOCHABER. 



413 



the west, is evident from the nature of them ; several of a pink coloured felspar, 

 having been traced by me to a dyke of the same peculiar rock a few hundred yards 

 to the west, from which they had evidently been derived. Another circumstance 

 proved this still more strikingly. In one place, a few hundred feet above Loch 

 Treig, I observed a series of rocky knolls, in an east and west line. The parts of 

 these knolls which were smoothed and woi-n down were uniformly to the west, 

 whilst their rough faces were all to the east, thus — 



Westr 



lEast 



It was clear, on an inspection of these knoUs, that they had been worn down on 

 their west sides ; and the smoothed sides a were so close to the knolls respectively 

 to the west of them, that nothing except some fluid, charged, it may have been, 

 with drift, could have possibly reached and acted on them. 



This last point was still more palpable, in several places, where there were 

 narrow smooth-sided troughs, more or less steep, on the sides of hills. These 

 troughs had apparently been natural fissures in the rocks, which had been smoothed 

 by the long-continued action of water ; for the notion that ice could have entered 

 and rubbed them, was entirely precluded by their narrowness, situation, direction, 

 and other circumstances. 



M. Agassiz, in the paper before alluded to, says that he will never forget the 

 impression he experienced " at the sight of the terraced mounds of blocks which 

 occur at the mouth of the valley of Loch Treig, where it joins Glen Spean. It 

 seemed to me (he adds) as if I were looking at the numerous moraines of the 

 neighbourhood of Tines, in the valley of Chamounix." These terraces of blocks, 

 thus likened to moraines, are, I presume, the accumulations of blocks on the lower- 

 most horizontal shelf, which is very conspicuous at the entrance to Loch Treig on 

 both sides of the valley. On this shelf there are multitudes of blocks, just as in 

 many other parts of the valleys, where this shelf and the others occur. But this 

 fact is perfectly consistent with the theory, that these shelves were formed by 

 water, and, indeed, can be explained on no other, when it is considered that they 



■T form at Loch Treig, as at every other place, a line absolutely horizontal, — a quality 



H| which, I presume, no moraine ever possesses. 



^B The only place where I observed an accumulation of blocks, at all resembling 



^B a moraine, is on the east side of Glen Spean, near a place called the Rough Burn, 



I 



