SBtAKiHG tRUMPETS. 



289 



pets, that the augmentation of found, in every circumftance. General con^ 

 is not owing to the reflection of fonorous rays, confequently 

 there exifts no reafonfor feparating the caufe which augments 

 the found in thefe inllruments, from that which ftrengtbens it 

 in trumpets and hunting horns; that the different founds pro- 

 duced in the two cafes are owing to the vibration of the air in 

 the tubes, and their ftrengths or their inteniities, to the aug- 

 mentation of the amplitude of their vibration, arifing from the 

 greater impulfe which the air neceflarily receives when it is 

 enclofed in a tube. 



Experiment (A). 



The tubes and the fpeaking trumpet of pafleboard. 



The interior diameter of the tube of the fpeaking trumpet is 

 0™. 038, that of the exterior diameter of the enlarged part = 

 0™. 210. The length of the tube = 0". 4, and the length of 

 the enlarged part == 0™. 2. 



Experiment (B)* 



The fpeaking trumpet was of tin, as well as the tubes. 



The interior diameter of the tube of the fpeaking trumpet 

 = 0"*. 035, that of the exterior diameter of the enlarged part 

 = O'^. 290, the length of the tube = O"*. 36^ and that of the 

 enlarged part = 0.25. 



e Vol, IX.— December, 1804. 



U 



With 



