93 



inclinations of the slate and sandstone, and the relations of these to 

 the granite centre and the numerous dikes. On this and most of 

 our Excursions our departure will be taken from the shores of Brodick 

 bay, the unrivalled grandeur and beauty of which attract the greatest 

 number of summer visitants. For a few days' sojourn new induce- 

 ments are now afforded by a fine spacious hotel on a beautiful site at 

 Invercloy, on the south side of the bay. Here and at several other 

 points on the east coast steamers call six times in the day during the 

 summer months. 



62. The rock on the shore at Invercloy is a conglomerate of 

 the age of the coal a member, in fact, of the coal formation. 

 Murchison, Sedgwick, and Ramsay have classed it as a lower member 

 of the new red ; but, as already stated (Art. 48), on evidence which 

 we think inconclusive. The inland cliff marking the old coast line 

 is well seen on the Invercloy shore, and extends far up both sides of 

 Glencloy. The lower part of the glen, much of the plain of Brodick, 

 and the marshy grounds at the head of the bay, are but an expansion 

 of the terrace which formed the sea bottom, when the tides and 

 waves were carving out the cliff. The alluvium and rolled stones 

 form, however, but a thin covering to the subjacent sandstone, which 

 appears in the river bed a little way up the glen. On the north-west 

 the sandstone is quarried upon the line of cliff, and forms a tolerable 

 building stone. The dip is nearly south, at about 25. By the side 

 of Brodick wood, adjoining the handsome new school house lately 

 erected by the Duke of Hamilton, a vein of pitchstone occurs in the 

 sandstone. The contact is not seen at either surface, so that the 

 thickness cannot be ascertained ; a portion only of the front appears 

 by the side of a lane, showing a prismatic structure in the rock, and 

 an underlie in the vein towards the west. In large blocks lying 

 loose upon the surface in the course of the vein, which here seems 

 stript of the sandstone through a considerable breadth, a similar 

 structure is seen. The colour is bottle-green, and specks of red 

 felspar disseminated in the base give the rock a porphyritic texture, 

 approaching that of pitchstone porphyry. The direction is nearly 

 south-east and north-west ; but the vein cannot be traced either way 

 beyond the limited portion here exhibited. It is probably a con- 

 tinuation of one of the many beds or veins of the Corrygills shore, 

 which we shall notice in another Excursion. A dike of disintegrating 

 ironshot greenstone, forming a bank behind the school house, has 

 an angular course with respect to the vein ; but the nature of the 

 ground does not permit their connection to be observed. In the 

 opposite direction the dike intersects the inclined strata of sandstone, 



