SEIL. GENERAL DESCRIPTION. 127 



straits ; the varied mountains of Mull, and of the Appin 

 and Morven lands, rising blue in the distance. 



Seil is about three miles in length and two in breadth, 

 but of a very irregular shape ; protruding in long points 

 parallel to its two principal boundaries. It is naturally 

 divided into three ridges, separated by two vallies in 

 the same parallel direction ; and as these ridges coincide 

 with the geological disposition of its rocks, on which 

 indeed they depend, they afford a useful guide in de- 

 scribing or investigating its structure. The northern- 

 most is the most elevated and the most rugged, rising 

 to a height apparently exceeding 800 feet, and presenting 

 to the sea, on that side of the island, a series of naked 

 precipices. The second, or middle ridge, is scarcely half 

 as high, and is prolonged more decidedly than the former 

 in a north-easterly direction ; presenting, in many parts, 

 faces of bare rock, yet descending to the sea at each 

 end by flat and verdant shores. A second valley divides 

 it from the last ridge, which is low and narrow, and 

 reaches also in the same direction from sea to sea ; being 

 characterized, even at a distance, by its grey colour and 

 by the bare rocks that protrude along the whole of its 

 course. At its eastern side a flat shore succeeds ; much 

 indented, but verdant and fertile ; as is the greater part 

 of the island wherever the form of the ground admits 

 of cultivation. The section of the rocks which accom- 

 panies this description will also convey an adequate idea 

 of the form of the land. In describing them I shall 

 follow the order adopted in Kerrera. 



THE section will show,* that the lowest rock is clay 

 slate, the extent of which is such as to occupy the 

 larger part of the island. At the north-western side, 

 but a small portion of that substance is however to be 



Plato XXII. fig. 1. 



