Chap, xxxii.] VIBRATIONS OF A STRING. 437 



fundamental or primary note of the string. Now let 

 the string be damped at the centre by one finger, and 

 let it be plucked at the centre of one half, the string 

 will divide 



itself into two ^J^Z <Z ^-gjgff 



equal parts, 



each of which Fig. 188.-The Vibration of a Steng sounding 



its Fundamental Note. 



will vibrate, 



the centre being motionless even when the finger 

 is removed, as shown by a rider remaining on the 

 string at that point while others are thrown off. The 

 string will now utter the octave of the first note, 

 a note, that is, produced by double the number of 

 vibrations of the first, and, therefore, also the first 

 harmonic of the primary. In the same way, if the 

 string be damped at a third of its length, on plucking 

 it in the middle of this third it will divide into three 

 equal segments, each vibrating in a similar way 

 (Fig. 189). There will be two points at which the 



A, A 



C D B 



Fig. 189. Vibration of a String damped at a Third of its Length. 



paper rider will not be tossed off. The note produced 

 will be the second harmonic. The points where the 

 string remains at rest are called nodes, and the parts 

 between the nodes which are in movement are called 

 ventral segments. By damping the string at one- 

 fourth of its length, it will be caused to vibrate in 

 four segments, and the fourth harmonic will be pro- 

 duced, and so on. 



Now the string, when it vibrates in its whole 

 length, produces its fundamental note of a particular 

 quality, but that note is not a simple one. If a graphic 



