MINERALOGY OF THE REDHEAD. S47 



some of these exceeding four feet, others only a 

 few lines in thickness. These strata are divided 

 by perpendicular rents, (or backs as they are 

 termed by the quarrymen,) which run at right 

 angles to the line of bearing, are parallel to one 

 another, and often cause the rock to exhibit some- 

 what of a columnar appearance. This structure 

 has enabled the sea to make great encroachments, 

 and has contributed to give to the scenery 

 its characteristic feature of boldness. When 

 the sea undermines the base of these angu- 

 lar masses, they fall with a tremendous crash, 

 and leave the newly exposed surface of the rock 

 a mural precipice. But it often happens, that the 

 upper portions of the columns are too firmly wedged 

 by the surrounding rock to allow them to be dis- 

 placed, so that the inferior portions only give way, 

 and in this case, a small cave is formed, which is 

 very speedily enlarged by the surf of an exposed 

 and stormy coast. 



In the promontory of the Redhead, there are a 

 number of caves situated in the rocks of sand- 

 stone, and some of them are of considerable mag- 

 nitude. These afford the seal and the otter a 

 safe retreat during the breeding season, enable the 

 superstitious natives to contemplate the ghastly # 

 spectres of Pandsemonium, and have been sup- 

 posed to exhibit to the geologist a proof of the 

 sea having formerly exerted its influence at a 

 higher level than the ordinary rise of its present 



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