BARRA. GEOLOGY. 81 



apparent. In composition it exactly resembles granite, 

 and in the disposition of its parts it differs but little; 

 yet where most granites are covered with a dense coat 

 of gravel, of clay, and of mixed vegetable soil, this 

 rock is bare even to the very level of the sea. The 

 absence of precipitous faces and of the marks of violent 

 fracture will be found to arise from the same cause to 

 which the want of springs is owing, namely, its freedom 

 from fissures. There is no place in which water can 

 lodge, nor consequently where the power of frost can be 

 brought into action; that agent from which the violent 

 fractures of rocks seem almost entirely to originate. 

 Hence arises that peculiar character of the hills which 

 predominates in a greater or less degree throughout the 

 whole range of the Long Island. No serrated outline, 

 no spiry summits, no angles nor abrupt faces vary 

 their appearance ; one rounded and tame line separates 

 them from the sky. A few parts only of Harris and 

 of Lewis offer an exception to this general rule. 

 Nothing indeed can well be conceived less interesting 

 in a picturesque view, than the whole of this chain of 

 islands. Much amusing display of a sort of ichno- 

 graphic scenery, arising from the labyrinthine disposition 

 of the land and water, may be seen by ascending the 

 hills, but there is scarcely any where a subject for the 

 pencil. While the mountain outlines are tame, their 

 groups are without complication. No trees occupy the 

 valleys, no water-falls sparkle along the declivities, the 

 cliffs have neither magnitude of parts nor breadth of 

 disposition, the shores of the numerous bays are uni- 

 formly low, and the sea rocks have neither elevation 

 nor form to compensate for the dulness of the interior 

 country. 



THE rocks of Barra offer nearly as little instruction 

 to the geologist, as they display attractions to the lover 

 of landscape. Gneiss is the universal substance, and 



VOL. i. G 



