136 LUING. GEOLOGY. 



The southern extremity of Luing is low, but never abso- 

 lutely flat, and the highest ridge at the northern end seems 

 scarcely to exceed 600 or 700 feet. There is in this part 

 of the island a slight tendency to the formation of two 

 'distinct ridges, originating in the same cause as that men- 

 tioned in Seil, namely, the different nature of the rocky 

 strata ; but it is far less conspicuous, arid would perhaps, 

 but for the previous view of that spot, scarcely attract 

 notice. It has been remarked that all the strata of Seii 

 lie in a very even direction from S. W. by S. to N. E. 

 by N. The same disposition exists at the northern end of 

 Luing, as well as in the intermediate island of Torsa. At 

 the southern extremity of the island however, this direction 

 changes ; and the elevated edges of the strata are there 

 found lying on the north line of the compass, or some- 

 what more easterly. It will be seen in the map that the 

 outline of the land corresponds with these different direc- 

 tions of the strata. There is consequently a curvature or 

 a fracture of the strata somewhere towards the middle 

 of the island ; but I know not that it is possible to dis- 

 cover the point at which that takes place, or to determine 

 to which of those two causes the change of direction is 

 owing. Whatever it be, the difference is not great, as it 

 scarcely exceeds two points of the compass ; in strictness 

 perhaps, twenty-six or twenty-eight degrees. From general 

 experience it may be concluded, that the change in question 

 consists in a curvature of the strata ; and the circumstance, 

 in itself sufficiently common, is only rendered interesting 

 here, because, as will hereafter appear, most of the islands 

 of this division are disposed with tolerable exactness in 

 one or other of these directions ; while in none, except in 

 this, in Shuna, and in Jura, are both found united. If the 

 point at which it might be seen has merely been over- 

 looked, these remarks will direct future observers to the 

 place where it is to be sought. 



Whatever be the direction, the dip of the strata here, 

 as throughout the whole group, is to the eastward ; the 



