MECHANISM OF NATURE 



a number of elastic glass balls are suspended, and 

 the first one in the series is swung out of the per- 

 pendicular and allowed to strike the next one in 

 the series. 



Then, because the force acquired by the falling 

 ball is transmitted through every ball in the series 

 to the last ball, this will fly out of the perpendicu- 

 lar. But the intervening balls have remained at 

 rest; as far as we can perceive they have suffered 

 no change. 



For any ball between the first and the last, sub- 

 stitute a ball of lead equal in weight. Then, be- 

 cause the ball of lead is not elastic, it will get 

 dented, and the last one will not fly out. But 

 the change made in the lead ball will not consume 

 the force, for heat will be generated, and heat will 

 expand the surrounding air, and change after 

 change will take place as the natural result of 

 the change in the lead ball. 



Yet the quality which makes the glass ball dif- 

 ferent from the lead ball is not incapability of 

 change, but rather it is that a glass ball can re- 

 sume its original shape after being changed, which 

 constitutes the property of elasticity. 



Therefore, the glass balls have also undergone 

 a change, and in the transmission of force from 

 one body to another body, every intervening body 

 must undergo a change. 



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