A SUMMER RAMBLE AMONG THE HEBRIDES. 23 



treme breadth twenty-seven feet ; its height, where the roof 

 rises highest, from eighteen to twenty feet The cave seems 

 to have owed its origin to two distinct causes. The trap-rocks 

 on each side of the vertical fault-like crevice which separates 

 them are greatly decomposed, as if by the moisture percolat- 

 ing from above ; and directly in the line of the crevice must 

 the surf have charged, wave after wave, for ages ere the last 

 upheaval of the land When the dog-stone at Dunolly existed 

 as a sea-stack, skirted with algae, the breakers on this shore 

 must have dashed every tide through the narrow opening of 

 the cavern, and scooped out by handiuls the decomposing trap 

 within. The process of decomposition, and consequent en- 

 largement, is still going on inside, but there is no longer an 

 agent to sweep away the disintegrated fragments. Where 

 the roof rises highest, the floor is blocked up with accumula- 

 tions of bulky decaying masses, that have dropped from above ; 

 and it is covered over its entire area by a stratum of earthy 

 rubbish, which has fallen from the sides and ceiling in such 

 abundance, that it covers up the straw beds of the perished 

 islanders, which still exist beneath as a 'brown mouldering 

 felt, to the depth of from five to eight inches. Never yet was 

 tragedy enacted on a gloomier theatre. An uncertain twi- 

 light glimmers gray at the entrance, from the narrow vesti- 

 bule ; but all within, for full two hundred feet, is black as 

 with Egyptian darkness. As we passed onward with our one 

 feeble light, along the dark mouldering walls and roof which 

 absorbed every straggling ray that reached them, and over 

 the dingy floor, roppy and damp, the place called to recollec- 

 tion that hall in Roman story, hung and carpeted^fertSl black, 

 into which Domitian once thrust his senate in a frolic, to 

 read their own names on the coffin-lids placed against the wall 

 The darkness seemed to press upon us from every side, as if 

 it were a dense jetty fluid, out of which our light had scooped 

 a pailful or two, and that was rushing in to supply the vacuum; 



