TRESHINISH ISLES. GEOLOGY. 587 



present see only in the still more insignificant remains 

 of the Danes or ancient Gael ; and when the obscurity 

 produced by distance of time shall resemble that whicli 

 arises from distance of place, they may acquire that conse- 

 quence in the eyes of posterity which they now possess 

 in the blue and fading horizon. He who would enjoy 

 the pleasures of the imagination must not scrutinize ; let 

 him avoid the shores of Cairnburg. 



Fladda presents one uniform flat and uninteresting sur- 

 face, while Linga rises by a succession of terraces into 

 a hill which appears to be about 300 feet in height. This 

 occupies but a small portion of the island, the remainder 

 of it being, like the former, level and low. Bach is 

 the most remarkable of the chain, being distinguished 

 by a hill which in some positions has the appearance 

 of a hemisphere ; from which the whole island acquires 

 the semblance of an ancient shield with the umbo protu- 

 berant in the centre. It seems to equal Linga in height. 



The geological history of these islands is comprised 

 in a few words. They are all formed of trap rocks. The 

 uppermost bed, where two are visible, consists of basalt, 

 having a perpendicular fracture but no columnar forms. 

 The second is an amygdaloid containing indifferent speci- 

 mens of mesotype and analcime ; and where, as in some 

 places, a still lower bed is accessible, it is a repetition 

 of the upper basalt. In these respects, as well as in their 

 general characters, they entirely resemble the neighbour- 

 ing parts of Mull, Ulva, and Gometra, of which they may 

 in a geological sense be considered as detached portions. 



END OF THE FIRST VOLUME. 



MOVES, PRINTER, LONDON. 



