on the Eildon Hills. 



213 



support the opinion of their having been caused by the action 

 of water^ unless corroborated by being at corresponding levels 

 with the terraces. I assume, however, on Mr. Kemp's au- 

 thority, that such is the case. But as the terraces are believed 

 to have been formed by tidal action, that cause, if it produced 

 any effect at all upon the hard greywacke ridges, must have 

 cut away those parts which appear as indentations (see the 

 diagram), and which must therefore be considered as success- 

 ively the actual lines of beach; whereas Mr. Kemp states, "that 

 the protuberances correspond in their respective levels with 

 the terraces on the neighbouring hills." Again, the broad 

 inclined slopes between the elevated ridges, are covered with 

 green sward, and form inclined planes with pretty uniform 

 surfaces. Though I could nowhere cut through the sward 

 to the rock below, I think it probable that these inclined 

 hollows do " indicate the situation of softer intermediate beds 

 which the action of the sea has washed away, leaving the 

 harder beds comparatively bold and prominent*." But here 

 another difficulty meets us : if the tidal action was sufficient 

 to produce so marked an effect upon the projecting hard 

 greywacke ridges, the softer intermediate beds must have 

 been washed away to a much greater extent than they have 

 been, and would have shown greater inequalities of surface ; 

 whereas they are generally smooth and uniform, and but a 

 * few feet below the ridges. 



Again, wherever, either on the terraces or the intermediate 

 slopes, fragments of the rock were exposed, they were angular 

 and rough, with sharp edges, and did not show the least ap- 

 pearance of having been rounded or acted on by water. I 

 .could not find on Williamlaw, or on either of the Eildons, a 

 single pebWe, or gravel, or sand of any kind, indicative of the 

 former presence of water. All were sharp angular pieces of 

 the same rock as that of the hills respectively, to the exclu- 

 sion of all foreign material. Now, if the water remained long 

 enough at any single level to have left manifest and perma- 

 nent indentations upon the hard ridges, it must have had 

 ample time to convert the loose angular fragments which 



* In a little quarry above the road, at the foot of these inclined hollows, 

 the hard grey wacke is divided in different directions by a system of joints, 

 one set of which inclines from 6 to 8 degrees to W.S.W., coinciding with 

 the dip and direction of the hollows. This made me think at first that their 

 surfaces might have been modelled by these joints ; but they are too uniform 

 and continuous, and other appearances do not support this view. In an- 

 other adjoining quarry the dip is 80 N.N.W., with a W.S.W. and E.N.E. 

 strike, which nearly coincides with that of the inclined hollows. This can 

 only be seen in one spot, where a few thin beds of soft shale intervene, the 

 bulk of the rock being a coarse greywacke without bedding or cleavage, but 

 with strong joints, and assuming here and there a rude columnar structure. 



