126 



THE GEOLOGIST. 



the neighbouring glens. Some of these anomalies indeed assist in 

 proving the probability of the hypothesis • . . . the remainder, yet un- 

 accounted for, may perhaps be explained hereafter. . . . One short 

 ' line ' only is found in the upper Talley of Glen Eoy ; yet all the 

 sides exhibit a general equality of slope, form, and texture ; nor is any 

 side more than aD other, subject to the action of a visible wasting 

 cause. A great deficiency of the whole of the 'lines ' occurs also to- 

 wards the bottom of lower Glen Eoy, and many partial ones in other 

 places. Of these, some evidently arise from the rocky nature Gf the 

 margin ; and others may perhaps be the consequence of the coinci- 

 dence between the slope of the hill and the slope of the supposed 

 shore. But these causes will not account for them all ; nor are there 

 sufficient marks of the action of posterior waste to explain them. 

 The anomalies of Glen Eoy and Glen Spean in particular . . . seem at 

 present to baffle all explanation, and in this unsatisfactory state must 

 the argument remain. It were well if there were not further diffi- 

 culties to encounter in adopting this hypothesis, but it is necessary 

 to enumerate them. ... As the level of the upper 'line ' of Glen Eoy 

 is higher than those of many valleys which would at present afford 

 passage to the supposed waters of Glen Eoy into the sea, it follows 

 that water could not now stand at that level unless these apertures 

 were obstructed to at least a higher elevation. The determination 

 of the position of these imaginary barriers is consequently the next 

 point to be considered ; as well as that of their number, since possibly 

 two of these openings might be closed by a single obstruction. ; ' . . . 

 " The uppermost one is of such a height that the water standing at 

 that level would now flow out by Loch Spey and Loch Laggan, through 

 the valley of the Spey, into the eastern, and by Loch Eil, Loch Sheil, 

 and Loch Ness into the western sea. The two lower ' lines ' lying 

 below the barriers of Loch Spey and Loch Laggan, it would, under 

 similar circumstances, find its way through the three latter openiugs 

 only. The condition of the surrounding land must therefore have 

 so far differed at that time from its present state, that various dams 

 or barriers must have existed in the course of these openings. . . . The 

 conditions of the present barriers existing at the source of Loch Spey 

 and to the east of Loch Laggan, are such as to give no reason to ima- 

 gine that they have once been higher. ... By the removal of the sup- 

 posed barriers to a point below Dalchully, one obstruction would . . 

 answer . . . the purpose of confining the waters in this direction. If 

 this were a mass of alluvial matter occupying the strath in which the 



