220 THE CRUISE OF THE BETSEY ; OR, 



crooked oaks projecting from the steep sides of some dark ra- 

 vine. The various beds of which the cliffs are composed, as 

 courses of ashlar compose a wall, are of very different degrees 

 of solidity : some are of hard porphyritic or basaltic trap ; 

 some of soft Oolitic sandstone or shale. Where the columns 

 rest on a soft stratum, their foundations have in many places 

 given way, and whole porticoes and colonnades hang perilously 

 forward in tottering ruin, separated from the living rock be- 

 hind by deep chasms. I saw one of these chasms, some five 

 or six feet in width, and many yards in length, that descended 

 to a depth which the eye could not penetrate ; and another 

 partially filled up with earth and stones, through which, along 

 a dark opening not much larger than a chimney-vent, the 

 boys of the island find a long descending passage to the foot 

 of the precipice, and emerge into light on the edge of the 

 grassy talus half-way down the hill. It reminded me of the 

 tunnel in the rock through which Imlac opened up a way of 

 escape to Rasselas from the happy valley, the " subterranean 

 passage," begun "where the summit hung over the middle 

 part," and that " issued out behind the prominence." 



From the commencement of the range of cliffs, on half-way 

 to the shieling, I found the shore so thickly covered up by 

 masses of trap, the debris of the precipices above, that I could 

 scarce determine the nature of the bottom on which they rest- 

 ed. I now, however, reached a part of the beach where the 

 Oolitic beds are laid bare in thin party-coloured strata, and 

 at once found something to engage me. Organisms in vast 

 abundance, chiefly shells and fragmentary portions of fishes, 

 lie closely packed in their folds. One limestone bed, occurring 

 in a dark shale, seems almost entirely composed of a species 

 of small oyster ; and some two or three other thin beds, of 

 what appears to be either a species of small Mytilus or Avi- 

 cula, mixed up with a few shells resembling large Paludina, 

 and a few more of the gaper family, so closely resembling ex- 



