MOUNTAIN OF THE BELL. 253 



nomenoii is vHriously explained by travellers. The 

 Arabs believe that the bell belongs to a convent 

 buried under the sand. The Greeks have their 

 legends about saints, demons, and genii, who cele- 

 brate their respective mysteries under this incom- 

 prehensible precipice. Mr. Fazakerley says the 

 sound was louder or softer, according as the sand 

 was more or less pressed ; and that at the same 

 time a quivering or vibration was very sensibly felt. 

 Burckhardt observed nothing that could throw any 

 light on it ; nor did he discover the slightest mark 

 of volcanic action, to which he supposed the thun- 

 dering noise might be attributable. Perhaps the 

 miracle may be explained by the existence of a 

 cavity underneath, in which steam or rarefied air is 

 generated ; or by the moving of the fine white sand, 

 of which the bank is composed, over the moister 

 and harder sand beneath.* 



* Similar sounds are not uncommon in other parts of the 

 world. (See Family Library, No. LIV.) In a paper lately read 

 before the Geological Society in London, Sir John Herschel 

 suggests as the only probable explanation which occurred to 

 him of the sounds at Narkous, that they are caused by the 

 generation and condensation of subterraneous steam ; and be- 

 long to the same class of phenomena as the combustion of a jet 

 of hydrogen gas in glass tubes. He makes the general remark, 

 that wherever extensive subterraneous caverns exist, commu- 

 nicating with each other or with the atmosphere by means of 

 small orifices, considerable difference of temperature may occa- 

 sion currents of air to pass through those apertures with sufficient 

 velocity for producing sonorous vibrations. The sounds described 

 by Humboldt, as heard at sunrise by those who sleep on certain 

 granitic rocks on the banks of the Orinoco, may be explained on 

 this principle. 

 Vol. II.— Y 



