DISPLACEMENT 



only is its force transmitted, and at the same time 

 the wave (Def. 3) is broken up. 



And so in every transmission of force that we 

 can observe in mechanics, that material which con- 

 veys that force does not return unchanged whence 

 it came. 



The water that drives the mill-wheel may not be 

 returned to the mill-pond until it returns as rain 

 from above. 



The steam that drives the engine must be con- 

 densed before it may be returned to the boiler. 



Therefore, that wave which conveys force and 

 transmits it must be broken up, in transmitting its 

 force. But let it be otherwise, and let the wave 

 theory of the nineteenth century be true. 



And let Figure A represent two bodies B and C, 



and let the dots between them represent ether par- 

 ticles. 



Then it is evident that the mass of ether par- 

 ticles may not vibrate until there is some empty 

 space provided for them to vibrate in. (Axiom 

 III.) Therefore, let the line DE cut off a por- 

 tion of the ether particles, and let the remaining 

 major portion act as a wave to transmit force from, 

 the body B to the body C. (Hypothesis.) 



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