52 CONTEMPORARY SCIENCE 



The total load of each station being thus an average of 

 the individual loads of a number of consumers is, in gen- 

 eral, far less fluctuating than in the case of small generat- 

 ing and distributing systems, which supply principally 

 one class of consumer, a state of affairs that exists in 

 London, for instance, at the present time. It is true that 

 there may be exceptional cases, such as at Kilmarnock, 

 where a good load factor may be found in a small area, 

 but in this case the consumers are chiefly mills, which re- 

 quire current for many hours daily. 



There is no golden rule to secure cheap electricity. The 

 most favorable size, locality, and number of generating 

 stations in each area can only be arrived at by a close 

 study of the local conditions, but there is no doubt that, 

 generally speaking, to secure cheap electricity a wide- 

 spread network of mains is in most cases a very impor- 

 tant, if not an essential, factor. 



The electrification of tramways and suburban railways 

 has been an undoubted success where the volume of traffic 

 has justified a frequent service, and it has been remark- 

 able that where suburban lines have been worked by 

 frequent and fast electrical trains there has resulted a 

 great growth of passenger traffic. The electrification of 

 main line railways would no doubt result in a saving of 

 coal ; at the same time, the economical success would 

 largely depend on the broader question as to whether the 

 volume of the traffic would suffice to pay the working 

 expenses, and provide a satisfactory return on the 

 capital. 



Municipal and company generating stations have been 

 nearly doubled in capacity during the war to meet the 

 demand from munition works, steel works, chemical 

 works, and for many other purposes. The provision of 

 this increased supply was an enormous help in the pro- 

 duction of adequate munitions. At the commencement of 

 the war there were few steel electric furnaces in the coun- 

 try; at the end of last year 117 were at work, producing 



