226 APPENDIX A. 



We can then establish the general proposition 

 that motive power is, in quantity, invariable in 

 nature; that it is, correctly speaking, never either 

 produced or destroyed. It is true that it changes 

 form, that is, it produces sometimes one sort of 

 motion, sometimes another, but it is never annihi- 

 lated. 



According to some ideas that I have formed 

 on the theory of heat, the production of a unit of 

 motive power necessitates the destruction of 2.70 

 units of heats. 



A machine which would produce 20 units of 

 motive power per kilogram of coal ought to destroy 

 20 X 2.70 



7000 



of the heat developed by the combustion. 



20 X 2.70 8 , ,. , . . 1 



about > that 1S > less than 



7000 1000 



(Each unit of motive power, or dyname, repre- 

 senting the weight of one cubic metre of water 

 raised to the height of one metre.) 



Experiments to be made on Heat and Motive Power. 



To repeat Rumford's experiments in the drilling 

 of a metal in water, but to measure the motive 

 power consumed at the same time as the heat pro- 



