THIRTEENTH ANNUAL REPORT 37 



tically no smoke. There is no known method of eliminating 

 smoke from a boiler when it is worked under an overload. 

 The new boiler works so satisfactorily that there has been a 

 restoration of funds with which to install two Dutch ovens in 

 front of the two old boiler units. Plans have been drawn for the 

 reconstruction of these ovens. The necessary arch bricks for 

 making the Dutch ovens arrived from the United States, the 

 ordinary fire bricks from Hongkong, and the work of raising the 

 boilers 45.5 centimeters and reinstalling them has been completed 

 during the year. Under ordinary load these two boilers produce 

 practically no smoke. The elimination of smoke has always been 

 a serious problem when bituminous coals are used, but we believe 

 that the arrangement now in use in the Bureau of Science will 

 be satisfactory and should be extended throughout the city as 

 much as possible. 



Producer-gas plant. — The producer-gas generator and the gas 

 engine work satisfactorily. We have successfully used Batan 

 coal in the 67-horsepower producer-gas unit for a year and a 

 half, and the experiment has been vastly more successful than 

 I anticipated. The consumption of coal in the producer-gas 

 generator to generate gas used in the gas engine to operate a 

 direct-coupled dynamo varies from 1.6 to 1.7 kilograms per 

 kilowatt hour of electric current produced, whereas we used 

 more than 4 kilograms of Japanese or Australian coal in= our 

 steam unit to generate a kilowatt hour of electric current. We 

 have used other classes of noncoking coal satisfactorily in the 

 producer-gas unit. Experiments were carried on to ascertain 

 whether or not the producer-gas plant was capable of continuous 

 operation. The manipulation of the generator has been so per- 

 fected that it has to be cleaned one third as often as formerly ; in 

 fact, at present it scarcely needs special cleaning at all. For eight 

 months the producer-gas plant has been operated continuously, 

 day and night, except when it was stopped for cleaning and 

 repairs. A water spray in the vertical gas pipe from the gas 

 generator and also another in the horizontal pipe connecting the 

 vertical pipe with the scrubber cleans the gas more perfectly 

 and prevents the incrustation of tar and dust that previously 

 gave trouble. With proper care and adjustment a producer-gas 

 generator and engine is a very reliable prime mover, and its use 

 in this Bureau will result in great economy in the production of 

 electric current. The advantages of the producer-gas engine 

 over the steam engine will be still greater when we use the 

 exhaust gases for heating water for the Philippine General 



