62 GENERAL COMPARISON OF 



the sandstone being repeated near Eilan reoch after an 

 interval formed by the gneiss of Sleat ; and that portion of 

 it which is prolonged to Loch Alsh, being found regularly 

 alternating with the gneiss of that district. 



The connexions of the primary sandstone of the several 

 islands immediately in the vicinity of Sky, with that 

 island, with each other, and with the mainland, have also 

 been amply detailed, and it has been further shown that 

 this rock is prolonged to Rum, where it must be supposed 

 to terminate, since the prolongations of the strata meet 

 with the gneiss of Tirey and Coll. Whatever variations 

 may occur in these lines of bearing, they are not often 

 considerable, but must rather be considered as examples 

 of that undulation from which strata are seldom exempt. 

 In Rasay alone, it was seen that an essential change of 

 direction took place ; and it may be remarked that on 

 the adjoining shores of Applecross the same change 

 occurs ; the sandstone here assuming a different position, 

 which is maintained for a great space. The dips of the 

 gneiss present a general uniformity, but those of the 

 sandstone undergo material variations ; which however 

 are analogous to those irregularities that characterize it on 

 the adjoining continent. That rock will be shortly de- 

 scribed at some length in treating of the Sandstone 

 islands. It is only necessary here to remark, in anticipa- 

 tion, that no doubt can exist respecting the geological 

 connexion of all these masses of sandstone, though inter- 

 ruptedly scattered among the several islands ; nor that 

 it appertains to the primary class of rocks ; often alterna- 

 ting with the gneiss on which, in other places, it lies. 



In examining the secondary strata, the first in order 

 is the gryphite limestone, the connexions of which have 

 been so fully traced in the islands in which it occurs, that it 

 is unnecessary here to dwell on them. It is only neces- 

 sary to remark, that as the leading direction of this lime- 

 stone in Sky is north-easterly, it ought, if continued, to 

 appear in Rum. As it does not exist there, it is probably 



