188 LECTURES TO SCIENCE TEACBEES. 



string, throwing that also into motion, and the motion of 

 the second string will be evident to you by its throwing 

 off these little paper riders. And what is more remark- 

 able still is that the vibration communicated to the second 

 string will be subdivided as in the first string. This 

 subdivision will be taken up by the second string, in 

 precisely the same manner as it exists in the first. 



FIG. 2. 



These then are cases of the transmission of vibratory 

 energy through solid bodies, and the acceptance of it by 

 other bodies tuned to the same pitch as the first. 



Here is an illustration, however, of a more remarkable 

 kind. We have here a tuning-fork which is capable of 

 vibrating at precisely the same rate as this other tuning- 

 fork which is in my hand. I will place one of these forks 

 in front of a lamp, and in order to enable you to see 

 the experiment more clearly, I will cast a shadow of it on 



