240 RASAY. GENERAL DESCRIPTION. 



This island is estimated to be fifteen miles in length, 

 and where widest, three in breadth. Neither of its longest 

 shores differs much from an uniform line ; but the differ- 

 ences, slight as they are, and therefore the less noted 

 in the maps, are peculiarly important to a geologist, as 

 they are connected with changes in the nature of the 

 rocks, the relations of which they serve at the same time 

 to compare and determine. 



It may be considered as forming a single ridge, though 

 irregular and unequal in elevation at its different extre- 

 mities ; the change, which is somewhat sudden, taking 

 place near Brochel Castle and being accompanied by a 

 corresponding difference in the rocks which form the two 

 divisions. The average height of the highest and southern 

 division may be estimated at 1000 feet or thereabout, 

 and it presents, when viewed from the south-east, the 

 outline of a high table land surmounted by the single 

 flat-topped eminence of Dun Can, of which the height 

 appears to attain about 1500 feet. But it declines towards 

 the west by a general slope, terminating in low shores; 

 while the eastern side is, for the greater part, bounded 

 by a long range of cliffs of a mural character, intermixed 

 with those grassy slopes which are here, as in similar cases, 

 the result of the degradation of the rocks. In the interior 

 of the island, narrow as it is, are many irregular emi- 

 nences, mixed with others of a character so particular as 



felt than in the island under review ; die inaccuracy of its map being 

 so great, that it is almost impossible to reconcile any of the actual 

 bearings with those that are given ; and, consequently, to pursue from 

 place to place those detached portions of any individual rock which it is 

 important to trace accurately. The same cause renders it impossible to 

 give a true topographic detail of the rocks, but as great nicety hi this 

 respect is not very essential, the reader must be content to take them 

 with that latitude, both of position and dimension, which alone is attain- 

 able. There being a total want of an interior survey, there can of COUI>L- 

 be no local references. 1 have corrected some parts of the. present map 

 which stood particularly in need of it, but they bear so small a proportion 

 to thf whole, that it must still remain what it was, a mass of deformity. 



