EXCURSION XIII. 163 



entering the granite precipices in front of the base of Cior- 

 Mhor, and passing on over the col, in the direction of the 

 axis of Glen Rosa. The easiest pass into this glen is at the 

 western side of the col or ridge joining Cior-Mhor to the 

 base of Goatfell. In the hollow up which we pass we have 

 a whin dike beneath our feet, and granite walls on either 

 hand a pathway, in fact, has been formed by nature in the 

 disintegration of this dike. On reaching the summit we 

 observe a great dike, most probably a continuation of this 

 one, ranging right up the front of Cior-Mhor. When one 

 reflects upon the mode of origin of these two rocks, granite 

 and greenstone, it strikes one with wonder to perceive the 

 curious relations which they maintain, and the important 

 part in the physical condition of the region which the dikes 

 play. If the molten matter of greenstone had had full vent 

 here and overflowed, the interior pressure would have been 

 relieved, and the mountains of the granite nucleus would 

 have stood at lesser altitudes. M. Necker goes so far as to 

 suppose it quite possible that the excavation of Glen Rosa 

 may have been determined by the great dike above noticed. 

 In the lower part of the glen the river runs upon it, between 

 high granite walls, for a long distance ; and it crosses S. into 

 Glen Shirag. It is thus by far the most continuous dike yet 

 traced in Arran. 



Up till the year 1822 this path was known as practicable 

 only by shepherds, some of whom occasionally used it. But 

 in that year two enterprising young ladies, Miss Alison and 

 Miss Crooks, both from near Kilmarnock, but residing at 

 Brodick, having arrived on a summer afternoon at the top of 

 the ridge by passing up Glen Rosa, determined to try the 

 descent into Glen Sannox, and return by the coast road. 

 With great difficulty and loss of time they made good the 

 descent ; but were so late on arriving at Brodick that all the 

 young men of the village had started off in parties, in differ- 

 ent directions, to search for them. Their tale excited no 

 small wonder. 



