MUSICAL MOUNTAIN OF EL-NAKOUS. 243 



not pretend to answer these questions, but we 

 trust that some philosopher competent to the 

 task will have an opportunity of examining these 

 interesting phenomena with more attention, and 

 describing them with greater accuracy. 



The only person, so far as I can learn, who has 

 visited El-Nakous, since the time of Seetzen, is 

 Mr. Gray, of University College, Oxford ; but he 

 has not added much to the information acquired 

 by his predecessor. During the first visit which 

 he made to the place, he heard at the end of a 

 quarter of an hour a low continuous murmuring 

 sound beneath his feet, which gradually changed 

 int pulsations as it became louder, so as to re- 

 semble the striking of a clock, and at the end of 

 five minutes it became so strong as to detach the 

 sand. Returning to the spot next day, he heard 

 the sound still louder than before. He could not 

 observe any crevices by which the external air 

 could penetrate ; and as the sky was serene and 

 the air calm, he was satisfied that the sounds 

 could not arise from this cause.* 



* See Edinburgh Journal of Science, No. xi., p. 153, 

 and No. xiii., p. 51. 



