EXCURSION XIV. 171 



for the purpose of defending this landing-place, one of the 

 best in the bay and at its entrance. There is a considerable 

 body of coarse greenstone here intruded as a bed among the 

 strata of sandstone, pieces of which are entangled in the 

 greenstone, and altered to the condition of quartz rock. The 

 greenstone is traversed by long continuous veins of a finer 

 kind approaching to basalt, probably cotemporaneous. The 

 rock is divided into large rhombic blocks, but the surface has 

 no resemblance to a basaltic pavement. On the shore at 

 Whiting Bay there are multitudes of dikes, appearing in 

 singular relations to one another intersecting, bifurcating, 

 uniting, and separating again, entangling and altering the 

 sandstone, and so on relations that it would be tedious to 

 describe in detail. The shore is covered with granite 

 boulders, one of which, near the south-east end of the bay, is 

 larger than any boulder south of Brodick, with the exception 

 only of the Corriegills boulder. It is remarkable that one so 

 large should be found so far from the granite centre. 



79. A little farther S. a fine glen opens to the west; this 

 is Glen Eais-dale, at the head of which there is the highest 

 waterfall in the island, bearing the name of Eais-a-Chranaig. 

 The stream descends over trap and sandstone in two fine 

 falls through more than 200 feet ; and here, as throughout 

 the rest of its course, the scenery is highly picturesque. On 

 the south side there is a trap dike, 10 feet wide, cutting the 

 sandstone and passing into the overlying mass of greenstone. 

 The contact of these overlying masses with the sandstone 

 shews a remarkable change. The rock has lost its red colour, 

 and becomes a white felstone, slightly porphyritic. Farther 

 down, the ordinary laminated character is gradually assumed. 

 On a terraced bank to the right of the fall there are the 

 remains of an ancient fortress, concealed amid wild wood, 

 which appears to have been the strongest of all the forts of 

 the ancient inhabitants, with the exception of that at Druma- 

 doon. The wall, formed of huge slabs, without lime, is 25 

 feet thick and 90 yards in circuit. " From the situation of 



