APPENDIX 875 



— such an expression has no meaning — it is energy 

 which is unavailable for further transformations. 



The matter in which we choose to say that this 

 energy is inherent has become inert. Let us substitute 

 for the Carnot engine the actual steam-engine of a 

 ship, the condenser of which is cooled by the sea water 

 which is taken in, and which is then heated and flows 

 out again into the sea. The heat derived from the 

 source, that is, from the furnace of the boiler where 

 coal is burned to raise steam, thus passes out into the 

 sea. Now the heat capacity of the sea is so great 

 that the temperature of the water is not appreciably 

 raised by this heat, which drains into it from the 

 engine : even if it were appreciably raised, the heat 

 would be conducted into the earth, or would be radiated 

 out into space, and would then raise the temperature 

 of the material bodies of the universe. But let all 

 this heat remain in the sea. It then simply raises the 

 temperature of the water by an exceedingly small 

 amount, and the motions of the molecules become in- 

 finitesimally increased. But the heat becomes equally 

 distributed by conduction and convection throughout 

 the mass of the water in the sea, and as there are no 

 differences in adjacent parts there are no means where- 

 by the energy which thus passes into the sea can be 

 again transformed. 



A new order of things is the result of the processes 

 we have indicated. The segregated, available heat- 

 energy of material bodies has become transferred to 

 the un-co-ordinated, diffuse, unavailable energies of 

 the molecules which compose these bodies. The 

 transformations which we can effect depend on the 

 condition that the energy which we utilise is that of 

 aggregates of molecules which are in a different physical 

 condition, as regards this energy, from adjacent aggre- 



