TWELFTH ANNUAL REPORT 93 



few minutes, and are fairly well carried by the dynamo, although 

 sometimes as overloads. 



Producer-gas plant. — The new dynamo driven by the producer- 

 gas engine is unquestionably far more economical in operating 

 expenses than the generating steam units. Exact figures of 

 the cost of the production of power for the producer-gas plant 

 are being prepared, and they will be compared with that for 

 the dynamos driven by steam engines. The producer-gas plant 

 is operated from 7.30 a. m. to 11.30 p. m. In this way there 

 is no restriction in the use of the electrically driven machinery 

 and electric apparatus, and at the same time the boiler is relieved 

 from overload, thus prolonging its life and reducing the depre- 

 ciation and running expenses as well as reducing the production 

 of smoke by light firing. 



In estimating the advantages of the producer-gas engine over 

 the steam engine in this plant, one must remember that we use 

 the exhaust steam from the steam engine for heating to the 

 boiling point about 10,740 cubic meters of ordinary city water 

 per year for the Philippine General Hospital. When we run 

 the gas engine we have to heat this same amount of water by 

 live steam. We shall endeavor to devise a method of using the 

 exhaust gases of the gas engine for heating the water for the 

 Hospital, in order to effect greater economy. 



Engme room. — The total electric current generated and de- 

 livered at the switchboard, from July, 1912, to May, 1913, is 

 214,650 kilowatt hours as compared with 179,192 kilowatt hours 

 for the corresponding months of the last fiscal year ; an increase 

 of 16.56 per cent. 



The total cost of 214,650 kilowatt hours is 9=21,741.25, which, 

 expressed in unit cost, is 9=0.10129 per kilowatt hour against 

 9=0.10279 per kilowatt hour of last year; a reduction of 

 1.46 per cent in unit cost. Of the total current generated, 

 59.31 per cent was consumed in the Philippine General Hospital, 

 8.83 per cent in the College of Medicine and Surgery, and the 

 remaining 31.86 per cent in the Bureau of Science. 



Boiler room. — The total amount of steam generated in the 

 boilers, for eleven months — from July, 1912, to May, 1913 — is 

 11,042,120 kilograms as compared with 9,944,858 kilograms for 

 the corresponding months of last year; an increase of 9.93 per 

 cent. The total cost of generating the 11,042,120 kilograms 

 of steam at 120 pounds per square inch, gauge pressure, is 

 9=28,126.49. Expressing these quantities in unit cost, it gives 

 90.0025472 per kilogram against 90.0026839 per kilogram of 



