36 The Cause of Life and Motion 



time and amplitude ; and though the amplitude 

 may be changed in a line of vibration, the time 

 in that line will- always remain equal at all points. 

 The increase of amplitude being simply an 

 increase of lateral movement. 



The amplitudes of the various vibrations within 

 a bar, will remain nearly the same, respectively, 

 whether the bar is large or small. But about 

 the outside of the bar, they will change very 

 materially with its size. For as will be obvious, 

 the amplitudes of the slower vibrations about the 

 exterior, will increase in some ratio with the 

 bars' size, while the fine vibrations will scarcely 

 be affected. There will, therefore, be some 

 resultant action between the lower and higher 

 vibrations, by which the bar may be set in mo- 

 tion and which will reciprocate by gradual de- 

 crements with the forces which maintain its 

 molecular structure. If we should shorten one 

 of the bars we would destroy its original note. 

 For the two scales of vibrations, respectively, 

 from the base and the apex of the bar necessary 

 for its production, would not then come to rest 

 at the new axis of vibration, but would pass it 

 and neutralize the action. By this shortening, 

 we would get a new resultant action of less 

 amplitude, and the note would therefore, be high- 

 er than the previous one. 



If the bar should not be much shorter than 



