CuchulUn Hills in Skye. 87 



Ways, and inclined at a moderate angle towards theSE.,or pa- 

 rallel to Loch Coruisk.* Supposing this discovery to be con- 

 firmed, as I expect it will, by an examination of Ben Blaven, 

 it will add another to the many instances in which the tabu- 

 lar form of the trap-rocks, in relation to their neighbours, 

 whether stratified or not, has been overlooked, and which 

 must be considered of the highest importance, as respects 

 the theory of their origin. 



The relation of the western Cuchullins to the subjacent 

 rocks is most obscure ; and this portion appears, as has been 

 said, to have been more particularly examined by mineralo- 

 gists. Hence the opinion, that the transition from the com- 

 mon trap into hypersthene rock is insensible. The western 

 Chichullins are composed of the same rock as the others. 

 They are placed nearly in a right line, running probably 

 NNW. and SSE. ; and the summits are divided exteriorly 

 by four great corries, which are noticed in the map. The 

 summit, called Scuir-na-Panachtich, rises immediately be- 

 hind Brittle House, and may, perhaps, be accessible on that 

 side. It does not appear to yield in height to any other of 

 the range. The last summit towards the sea is Garsven, 

 which is not one of the highest ; but it is conspicuous by its 

 noble form from Scavig Bay, by which travellers usually 

 approach Coruisk, and whence Mr Thomson's noble and 

 faithful painting of the Cuchullins is taken. 



In all this range, the true hypersthene seems to pass in- 

 sensibly into one or other of the varieties of the trap rocks — 

 sometimes into a syenitic rock composed of distinct concre- 

 tions of felspar and augite (?) At others, into a minute 

 grained green trap rock, of iron hardness, and of which the 

 composition is undistinguishable. I was at first inclined to 

 think that the syenitic rock, just mentioned, might contain 



* Ltt speaking of directions by the points of the compass, I must be 

 understood with some latitude. Disregarding entirely the indications of 

 the needle in a district filled with magnetic rocks, I have attempted no- 

 thing as regards azimuths, but a general reference to the position of the 

 sun, or, more generally, to some distant well-marked part of the island, 

 as laid down on charts. 



