The Cause of Life and Motion 35 



of isochronous air waves would be produced by the 

 first bar and that no other bar of a different note 

 would be influenced, because its form would not admit 

 of its vibrating in time. This explanation would do 

 very well if these musical bars were like pendulums; 

 and if isochronous pendulums would vibrate in sym- 

 pathy with one another at considerable distances 

 apart. But since neither condition exists, the explana- 

 tion must fall to the ground. Pendulums do not vi- 

 brate syrnphathetically, because there are no force 

 vibrations sufficiently slow to transmit the action. 



It takes a great deal more power to vibrate a 

 bar of steel than it does to oscillate a pendulum, 

 and therefore, if the air were nothing more than 

 a quiescent fluid, pendulums of equal lengths 

 would vibrate from sympathy at considerable dis- 

 tances apart. In any case, the supposition of a 

 fluid being quiescent, is absurd, for such a prop- 

 erty could only exist in 'a mass whose component 

 elements were absolutely close fitting and im- 

 movable. 



We will now endeavor to find a cause for this 

 sympathetic action of the musical bars. Let us 

 suppose then, that two of these bars are secured 

 in vices at some distance apart, and that they are 

 exactly of the same size and texture and have 

 equal lengths exposed above the vices. In this 

 condition, we find that each bar has an equal 

 displacement of energy. In these displacements 

 we have an indefinite variety of vibrations, as to 



