MECHANISM OF NATURE 



On the short arm let 90 Ibs. weight be placed. 



Then it is evident that, in order to balance the 

 90 Ibs. on the fulcrum, 10 Ibs. of weight must be 

 placed on the end of the long arm. 



But gravity acts in this case as if the whole 

 weight were resting on the fulcrum,* which is the 

 centre of gravity. 



For either or both weights, substitute any other 

 pressure or force, and the result remains the same. 



Therefore, any other force acts in this respect 

 as gravity does, namely, as if the whole force pro- 

 ceeded from or was directed to the centre of 

 gravity. 



PROPOSITION XIII. 



Back of every change in material wrought by 

 force, yet within the finite circle of human reason- 

 ing, lies the cause of all change "life." 



It is because we live that we perceive change. 



All around us things die that other things may 

 live. All growth is accomplished by building up 

 that which has been dismembered for the use of 

 growing. 



And so intimate are life and death that they 

 must needs be simultaneous. 



There can be no plus without minus. 



* Any force manifestation where a movement of particles 

 or bodies can be perceived is ever intimately associated 

 with gravity, and those laws of gravity that have been 

 fully proved by Newton can be applied to many force 

 manifestations. 



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