Stanley's Memoir on a Cave at Cefn in Dcnbigshire. 47 



ed into fragments, which were carried still farther, while another, 

 not much smaller, was hurried up an acclivity to a distance of 

 150 feet. A. further proof that these limestone ranges, as well 

 as ranges of still harder rocks in the vicinity, have at some for- 

 mer period suffered by convulsions, is fully ascertained by the 

 inexhaustible quantities of boulder paving-stones with which 

 many parts of this coast abound, forming a constant source of 

 traffic between Liverpool and Wales, either for the purpose of 

 burning into lime, or breaking up for the macadamised roads in 

 the interior of Lancashire and Cheshire. One other supposition 

 may be given, respecting the former state of the waters and val- 

 leys of this district, dependent upon the existence of the barrier 

 in question, namely, that, instead of a deep lake abutting at once 

 against a rocky mound, like the waters of a canal or reservoir 

 against a lock-gate, or similar artificial check to their escape ; 

 the valley itself existed, not, indeed, in its present deeply exca- 

 vated form, but elevated above its present bed to the height of 

 about 100 feet, that is, to the level of the higher cave. On 

 which supposition, it is easy to conceive that it formed the bed 

 of a wide torrent, covered with shingly pebbles, brought down 

 from their parent rocks on the higher lands, from whence, the 

 waters had their source, and rounded in their progress by con- 

 stant attrition. Allowing, then, this latter supposition, there 

 can be no great difficulty in accounting for the partial and spar- 

 ing deposit of pebbles, in the lower flooring of the cavern. A 

 body of water rushing down from the distant higher lands, sa- 

 turated with loamy mud, would either bring with it a supply 

 of them, or, more particularly if caught up in its vortex, a 

 shingly accumulation of small sized pebbles *, similar to those 

 so commonly found deposited on the shores of streams and 

 lakes, would have been forced inwards. The quantity admit- 

 ted would of necessity be limited, for the cavern having in all 

 probability no exit at its further extremity, would, on being 

 filled after the first rush of the torrent, become a reservoir of 

 quiescent water, strewing the bottom with those pebbles alone, 

 collected near its mouth as it rushed in, and leaving them im- 

 bedded in its muddy sediment. And to the same cause we 



• Thej were so small and similar in size, that an average collection of 20 

 weighed little more than 10 oz., or about half an ounce each. 



