90 Professor Alex. B. W. Kennedy [April 21, 



impossibilities in connection with some complete industrial processes. 

 Let us take first the generation and distribution of electricity, a 

 matter which is of such keen interest now to so many of us, whether 

 from the point of view of economy in production or economy in our 

 quarter's bills ! 



The various stages of Fig. 5 tell a tale which, perhaps, may 

 interest you. They represent the gradually degenerative process by 

 which the chemical energy of combustion is converted into electric 

 light. To the left hand of the diagram is represented the boiler 

 process, and the various transformations are represented from left to 

 right, until the lamps are arrived at on the right hand of the figure. 

 Similar letters are used in each section of the figure for similar 

 quantities of energy. In each section the losses of the section 

 before are written off, and the heat actually carried forward is called 

 100 per cent. K represents the losses in the boiler, which is assumed 

 to have an efficiency of 80 per cent. H represents waste mainly due 

 to condensation in steam pipes, and also to the driving of pumps, 

 and other such losses inevitable in a central station. The third 

 section represents the whole heat which has been received by that 

 portion of the steam which actually found its way to the main 

 engines, and of this, G is the part unavoidably lost from thermo- 

 dynamic limitations. In Section IV. the heat actually received by 

 the engine is called 100 per cent. Of this, the area F is wasted, and 

 the remainder turned into work. Section V. shows the whole heat 

 turned into work by the engine as 100 per cent., of which the area 

 E represents the energy necessary to drive the engine itself, which, 

 therefore, never reaches the dynamo. In Section VI. the energy 

 received by the dynamo is taken as 100 per cent., and the area D 

 represents the dynamo losses, which are wonderfully small. The 

 energy — now in the form of electrical energy — which leaves the 

 terminals of the dynamo, is represented by 100 per cent, in Section 

 VII. Of this, a certain proportion, sometimes small, sometimes 

 large, but here represented by C, is expended in mains, transformers, 

 or batteries, and never reaches the lamps. Finally, at the right- 

 hand side of the figure we get the energy received by the lamps as 100 

 per cent., out of which only the small, almost insignificant quantity 

 A is turned into light, the huge remainder B being once more 

 converted into heat. If the size of the area A in Section I. be looked 

 at, it will be seen what an insignificant quantity of the whole heat of 

 combustion is actually and finally turned into its intended purpose. 



The result savours a little of the ludicrous. Let us go back 

 and review its possibilities. The losses K, I need not deal further 

 with. H represents losses about which we engineers feel very sore, 

 and which sometimes try our temper and our patience greatly, 

 and which are particularly persistent and hard to get rid of. 

 G and F, I have already dealt with. E and D do not look very 

 promising as fields for radical improvement. There are few things 



