CH. xxx. CHLADNI ON MUSICAL VfBRA TIONS. 269 



for the string will continue to vibrate in the same manner 

 till it comes to rest 



All these facts about vibrating strings were worked out 

 by Bernoulli, Euler, and Lagrange. Bernoulli also showed 

 how the air vibrates in pipes, and why the note they produce 

 depends upon the length of the pipe, and the sharpness 

 with which the air is forced into it ; but these experiments, 

 though very interesting, are too long to enter upon here. 



Chladni on the Musical Vibrations of Solid Bodies. 

 When it was once known that strings give out different 

 notes according to their length, weight, thickness, and 

 tension, and also that on any one string different notes are 

 produced by the formation of nodes or points of rest, the 

 foundation was laid for a full understanding of stringed 

 instruments. But musical notes can be produced in a much 

 simpler way than this. We know that by merely striking a 

 glass or a piece of metal we can get a clear and beautiful 

 note, and that these notes are different even in the same 

 glass when it is held and struck in different places. For the 

 explanation of these notes we must go to Chladni, a man 

 who, on account of his wonderful researches, has been called 

 the " Father of Modern Acoustics" or the study of sound. 



Ernst Chladni, the son of a professor of Law at Witten- 

 berg in Saxony, was born in 1756, and having the misfortune 

 to be the only son of an over-anxious father, his childhood 

 was dreary in the extreme. He tells us that though he was 

 kindly treated and had good teachers, yet he was never 

 allowed to go out of the house alone, or to see any boys of 

 his own age except at church. His father, indeed, never 

 allowed him to go even into the garden unless the day was 

 unusually fine, so that it is wonderful how he kept his health. 

 He was not sent to school till he was fourteen years old, 

 and then to so strict a master that he was but little better 



