210 NORTH RONA. GEOLOGY. 



the advantages of their social forms. Yet I shall not 

 be surprised if after the accomplishment of his only 

 wish he should again long for his now habitual home : 

 and expect that some future visitor will twenty years 

 hence find Kenneth Mac Cagie wearing out his life in 

 the subterranean retreat of his better days. 



LIKE Sulisker, Rona consists of gneiss, alternating 

 with beds of hornblende schist equalling or exceeding 

 it in quantity, and traversed by granite veins. The 

 gneiss is of the granitic character, resembling that of 

 Lewis, and the hornblende schist is distinguished by 

 the great profusion of garnets it contains. These are 

 so abundant that the weathered rock sometimes presents 

 an uniform red surface, the hornblende wasting away, 

 while the more durable garnet continues protuberant 

 above it. They are occasionally of a large size, attaining 

 the diameter of an inch or more, and occupying also 

 the veins of granite and of quartz which traverse the beds. 

 In this case they are occasionally transparent, but always 

 too much fissured to admit of being rendered ornamental 

 by polishing. 



The most conspicuous of the granite veins is many 

 yards in diameter, and extends from the landing place 

 to the north side of the island, in a straight course 

 nearly north and south. It is remarkable for the mag- 

 nitude and beauty of the felspar it contains, and of 

 which it affords specimens of much interest to collectors. 

 This is of a salmon colour and pearly lustre, translucent, 

 and reflecting much light from the interior laminae. 

 Sometimes it is so intermixed with quartz as to form 

 graphic granite of various aspects, and occasionally, 

 as in East Rona, of a laminar structure. The quartz 

 of this vein is also remarkable for the variety which 

 it presents. It is sometimes grey and opaque, at others 

 smoky brown and transparent, or white and opaque, 



