HARMONICS, OR OVERTONES. 



185 



resonator, this is clearly distinguished, to the practical ex- 

 clusion of all others, and we can thus analyze complicated 

 chords into each of their constituent parts. This experiment 

 shows the similarity between chords, resolved into their con- 

 stituent parts, and single tones, resolved into their harmonics, 



FIG. 14 a. 



FIG. 14 b. 



or overtones. The resonators of Helmholtz, which are open 

 at the larger extremity, are infinitely more delicate than those 

 in which this is closed by a membrane. 1 



A very beautiful and instructive point in the present dis- 

 cussion is the following : All the overtones are produced by 

 vibrations of segments of the string included between the 

 comparatively still points, called nodes ; and, if we cause a 

 string to vibrate by plucking or striking it at one of these 

 nodal points, we abolish the overtones which vibrate from 

 this node at a fixed point. For example, if we pluck the 



1 HELMHOLTZ, Theorie physiologique de la musique, Paris, 1868, p. 67, et seq., 

 and p. 487. 



