EXCURSION I. 59 



corrie, there stand out here and there enormous pillars of the 

 rock, detached from the cliff behind, resting on a basis 

 which is rapidly giving way under the active agents of waste 

 in this changeful climate, and threatening a speedy descent 

 into the valley of the Garbh-Alt. The rugged outlines of 

 the Goatfell group bound our view on the east, the distant 

 landscape being shut out by the intervening ridges ; and the 

 eye from this point does not take in a single human dwelling, 

 or other sign of the abode of man. No sound reaches the 

 ear but that of the crystal rills trickling from the clefts of 

 the granite, the hum of insects on the wing, or the twitter 

 of the solitary stone-chat, as it flits from rock to rock. The 

 solitude is complete, the silence solemn and impressive. Our 

 perfect isolation amid such a scene the vast dimensions of 

 the objects ai'ound us, and their expression of power, are 

 true elements of the sublime, and awaken the most pleasing 

 and elevating emotions. There is a delightful consciousness 

 of a new activity in the fancy, and an increased buoyancy 

 and intensity in the feelings. To the geologist there is 

 another source of the sublime in contemplating the effects of 

 the mighty forces which have rent the crust of the earth, 

 raised these mountain masses from the fiery depths beneath, 

 and scooped the glens and corries out of the solid rock. 



28. The cliff on the north side of the corrie shews some in- 

 teresting dikes. One of these is of green pitchstone, and cuts 

 the granite sheer through in a north and south direction 

 from bottom to top of the cliff. It is four feet wide, prismatic 

 across, and, owing to the more rapid disintegration, depressed 

 below the level of the granite. The contact does not present 

 any peculiar change in either rock, such as usually marks 

 the plane of contact of pitchstone and the sedimentary strata. 

 The pitchstone is decomposed into a thin white film in many 

 places along the outer edge of the dike, next the granite, in 

 consequence, probably, of the oxidation and removal of the 

 iron which enters into its composition. The dike is in some 

 parts of its course obscured by debris, but upon the whole is, 



