ICE-EROSION IN THE CTJILLIN HILLS, SKYE. 



241 



easterly spurs of Clach Glas and Blath-bheirm. Each of these ten branches has a 

 precipitous face towards the north and a less steep slope towards the south, though 

 the chances against such a coincidence as an accident are more than a thousand to one. 

 It may be noticed, too, that the only 

 parts of the main ridge of the Cuillins 

 which have the E. to W. direction, viz., 

 the Basteir and Sgiirr a' Mhadaidh, are 

 also steeper on the north side than on 

 the south (fig. 7). 



The distribution of the cirques or 

 true corries in the Cuillins and the 

 adjacent Red Hills also suggests a con- 

 nection with the direction of sunshine. 

 Helland* long ago pointed out that 

 in Norway most of the cirques face 

 northward, or towards some point of 

 north ; and something of the same kind 

 is to be noticed in the Skye mountains, as appears from the following table giving the 

 aspects of 52 cirques : — 



N.W 



S.E. 



Fig. 9. —Transverse section of lower part of the Sgurr Sgumain ridge, 

 to show its asymmetric form. The dotted line gives for com- 

 parison the symmetrical cuspate cross-section of the higher 

 part of the ridge. Scale, about 3^ inches to a mile. 



W.N.W. 



4 



N.W 



2 



N.N.W. 



3 



N. 



8 ) 



N.N.E. 



4 



N.E. 



8 I 



E.N.E. 



2 



E. 



6 





37 



20 



E.S.E. 



1 



S.E. 



3 



S.S.E. 



1 



S. 



1) 



S.S.W. 



4 



s.w. 



2 J 



W.8.W. 



1 



W. 



4 





15 



The inequality here, though decided, is not overwhelming, and except in con- 

 nection with the foregoing remarks would not call for notice. It should be remembered, 

 however, that we have included here the interior of the district, where the influence 

 of aspect is much less evident than towards the exterior. If we separate the interior 



from the exterior corries, we find — 



N., etc. S., etc. 



Interior 

 Exterior 



18 

 19 



12 

 3 



Here the prevalence of the northerly aspect in the second group of cirques is very 

 marked. The basaltic plateaux beyond the mountain district owe their form almost 

 everywhere to their geological structure, but even here there are some significant 

 exceptions. An Cruachan, for instance, a hill to the west of Glen Brittle, presents a 



* Quart. Jonrv. Geol. Soc, vol. xxxiii. pp. 162, 163, 1877. 



