PRACTICAL OPERATION OF DYNAMOS. 237 



Frequently a newly installed electric light plant starts out on 

 the flat rate system, which it retains until the increasing demand 

 for current exceeds the capacity of the station. Then the meter 

 system is adopted to curtail the waste of current and so relieve 

 the situation. 



The pecuniary saving incident to the use of the meter system 

 is great enough to give the customer the service he needs at 

 a reduced total cost, to cover the cost of installing and maintain- 

 ing the meters and the cost of the extra book-keeping involved, 

 and to yield, in addition, an increased margin of profit to the 

 station management. The advantage to the station may not 

 appear, however, -unless the demand for current is such that it 

 would exceed 'the station capacity if the flat rate system were 

 used. This is evident when we consider that a very slight saving 

 in the cost of operating the station would be effected by decreasing 

 a moderate station load by adopting the meter system ; whereas 

 the large income that is in sight when the demand foi current 

 under the flat rate system exceeds the station capacity may be to 

 some extent realized by the adoption of the meter system. 



