ON WAVE MOTION. 



Thus, in deep-water waves, where 

 (5) V=^/^-. q=h G=iV, 



411 



9^, 

 qn 



BC=iOF=OE. 



Ill short capillary waves, seen round the stem, q = ~^, and no 

 echelon waves are discernible. 



Sound waves in air are propagated with the same velocity for all 

 wave lengths, otherwise music would be impossible and could not exist ; 



I 





Fig. 1. 



he g==0, </)— ^, and the echelon waves are merged in the wave front. 

 This is revealed in the bnllet photograph, whore the bow and stem wave 

 are taken very clear and distinct in the air. With the very sharp point 

 of the new bullet, the liead is seen penetrating the bow wave, as on the 

 sharp bow of a steamer. 



5. Sound waves are due to vibration of the air, propagated with 

 velocity about 1100, f/s, and generated for music by a vibrating body, 

 such as a violin string, a piano wire, the voice, or an organ pipe (fig. 1). 



