Vi 



SOUND AND MUSIC 



Causes Media Waves Periodic Motions Musical Non - 

 periodic Noises Waves in Air, Water, Earth Reflection- 

 Refraction Telocity Numbers of Waves Length Vibra- 

 tions of Strings Rods Plates Bells Resonance. 



THE eye and light are the means by which we are enabled 

 to move to and fro on the earth, to work safely and 

 skilfully. By the ear and sound intercourse is carried 

 on between man and man. The laws of light have 

 afforded many arguments in favour of the making of 

 the ether by which it is transmitted, and also of the 

 molecules of matter for which its properties are measured, 

 and the order in which it puts to the finest test. The 

 laws of sound, the modes in which it is originated and 

 conveyed, contribute also a rich quota of facts sustaining 

 the same contention. 



Even in the infancy of scientific investigation, a true, 

 though necessarily vague, idea of the cause of sound was 

 formed. The language of Aristotle is such that, as has 

 been said, admirers in their enthusiasm might, without 

 much difficulty, draw from it a pretty full and accurate 

 account of the manner in which it is produced and 

 propagated. That it is caused by the motions of a 

 vibrating body borne through the air to the ear was 

 universally held. At the same time the nature of the 

 motions was unknown. 



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