PRACTICAL OPERATION OF DYNAMOS. 



231 



included in the tabulated costs of operation of the station and dis- 

 tributing system. The cost of repairs is the average for three 

 years. A portion of the fixed charges, namely, repairs and 

 insurance, are tabulated in accordance with actual expenditure ; 

 and the remainder, namely, interest, depreciation, and taxes, are 

 estimated at n per cent., that is, interest 6 per cent., deprecia- 

 tion 4 per cent., and taxes I per cent, although as a matter of 

 fact the investment is covered by municipal bonds which bear 

 interest at 3.5 per cent, and the plant pays no taxes. This plant 

 supplies current to consumers on a sliding scale of flat rates, that 

 is so much per month for each lamp installed, the rate being less 

 the greater the number of lamps installed by an individual con- 

 sumer. This station is operated 15 hours per day, 365 days per 

 year. 



Station B is a 405 kilowatt plant owned and operated by a 

 city of 7,500 inhabitants in Connecticut. The equipment in- 



EXPENSE ACCOUNTS FOR ONE YEAR OF Two ELECTRIC PLANTS. 

 A = 225 kilowatt plant. B = 405 kilowatt plant. 



eludes four 60 kilowatt direct current generators each direct 

 connected to a 100 horse-power engine, one 165 kilowatt direct 



