Hull— Raised Beach of Cantyre. 7 



I venture to offer a few remarks on the several forms in which, 

 these monmnents and vestiges of ancient sea-action present them- 

 selves. 



Along the western coast, north of Machrihanish Bay, the rocks of 

 Mica-schist (forming the fundamental rock of the country) assume 

 the most fantastic forms, and their wrinkled and weather-beaten 

 surfaces often bear the closest resemblance to the knotty stem of an 

 old oak. The beds are often intensely crumpled, but are traversed 

 by a system of joints, running generally in a north-westerly direc- 

 tion, and cleaving the rock in nearly vertical fissures of wonderful 

 regularity (see Fig. 1). In the case of this rock the action of the 

 sea has resulted, not in the formation of caves, but of chasms, hewn 

 out along these joints, sometimes to a depth of 40 or 50 feet. One of 

 the most striking of these fissures is represented in Fig. 1. It is 

 bridged across for the road at the spot from which the sketch is 



Fig. 1. — Sea-woen Fissures in Mica-schist, beyond the Peesent Eeach of 

 THE Sea. Eaised Coast of Cantyke. 



taken, and in looking up the vista between the two vertical walls, 

 the impression conveyed is that the walls have been rent asunder, 

 so like are they to each other, and so true is their parallelism. Such 

 an impression, it need scarcely be stated, would be erroneous ; the 

 true explanation being, that the intervening portions of the rock 

 have been swept away, The jointage has been here evidently the 

 gTiide to the sea-action, and the waves, taking advantage of those 

 places where a number of fissures, running close together in parallel 

 planes, has offered to their action a line of weakness, have loosened 

 and carried away block after block, till such chasms are formed as 

 those here presented to us. We have only to step down a few 

 paces to the actual shore where the waves are at work among the 

 same rocks to observe the present mode of hewing out similar 



