INFLUENCE OF ELEVATION ON SOUNDS. 275 



magician, therefore, who is desirous to impress upon his 

 victim or upon his pupil the conviction of his supernatural 

 power, to carry him, under the injunction of silence, 



to breathe 



The difficult air of the iced mountain's top, 

 Where the birds dare not build, nor insect's wing 

 Flit o'er the herbless granite, 



he would experience little difficulty in asserting his power 

 over the elements, and still less in subsequently com- 

 municating the same influence to his companion. 



But though the air at the tops of our highest mountains 

 is scarcely capable of transmitting sounds of ordinary 

 intensity, yet sounds of extraordinary power force their 

 way through its most attenuated strata. At elevations 

 where the air is three thousand times more rare than that 

 which we breathe, the explosion of meteors is heard like 

 the sound of cannon on the surface of the earth, and the 

 whole air is often violently agitated by the sound. This 

 fact alone may give us some idea of the tremendous nature 

 of the forces which such explosions create, and it is 

 fortunate for our species that they are confined to the 

 upper regions of the atmosphere. If the same explosions 

 were to take place in the dense air which rests upon the 

 earth, our habitations and our lives would be exposed to 

 the most imminent peril. 



Buildings have often been thrown down by violent 

 concussions of the air, occasioned either by the sound of 

 great guns or by loud thunder, and the most serious 

 effects upon human and animal life have been produced 

 by the same cause. Most persons have experienced the 

 stunning pain produced in the ear when placed near a 

 cannon that is discharged. Deafness has frequently been 

 the result of such sudden concussions, and if we may 

 reason from analogy, death itself must often have been the 

 consequence. When peace was proclaimed in London in 



