540 



EXPERIMENTS AND INQUIRIES 



than it can possibly be by a sudden impres- 

 sion of the blast. It is proposed, at a future 

 time, to ascertain, by experiment, the actual 

 compression of the air within the pipe under 



different circumstances : from some very 

 slight trials, it seemed to be nearly in the ra- 

 tio of the frequency of vibrations of each 

 harmonic. 



Tahle xi. 



• A is the length of the pipe from the lateral orifice to the end. C, the pressure at which 

 the sound began. B, its termination,- by lessening the pressure ; D, by increasing it. E, the 

 note answering to the first sound produced by each pipe, according to the German method 

 of notation. F, the number showing the place of each note in the regular series of harmo- 

 nics. The diameter of the pipe was .35 ; the air duct of the mouth piece measured, where 

 smallest, .25 by .035 ; the lateral orifice .25 by .125. The apparatus was not calculated to 

 apply a pressure of above 22 inches. Where no number stands under C, a sudden blast was 

 required to produce the note. 



