PHILIPPINE COALS AS FUEL. 305 



During all of these tests the steam was used to operate a large duplex 

 steam pump, to drive the engine which furnishes the power to operate 

 the air compressor, the vacuum pump, the refrigerating machine and 

 many small motors, etc., for the laboratory and to supply live steam 

 throiTghout the building. At first I intended to take switch-board 

 readings, but the idea was given up as impracticable. Owing to the 

 intermittent use of steam for other purposes such readings would neces- 

 sarily be incomi)lete; but in Plates II to VII, I have given photographs 

 of the volt meter and ammeter indicator diagrams. An estimation from 

 these shows that an average of about 60 per cent of the steam produced 

 was used by the engine, and 40 per cent for other p»urposes, including 

 that condensed by radiation from the pipes. The equivalent evaporation 

 per indicated horsepower was assumed as 25 kilos of water, because of 

 the light and variable load of the engine. 



The portable drop-lever Howe scales used in making the weighings were care- 

 fully standardized and found to be correct; the meter was fitted with a gauge- 

 and regulators so that it was calibrated from time to time by actually weighing 

 the water passing through under the same head as it was fed into the boiler 

 and no error was at any time detected in the registrations of the meter. If 

 there was a slight error, being constant, it would affect alike all the tests and 

 therefore be negligible in securing data for comparative purposes. The boiler 

 feed pump was run intermittently and always at the same rate. The tem- 

 perature of the water entering the boiler from the heater was determined by 

 readings of a thermometer placed in a thermometer cup on the pipe just adjacent 

 to the boiler. The steam gauges were tested by comparing with the test-gauge 

 of the Crosby Steam Gauge and Valve Company, a standard instrument manu- 

 factured by Schafi^er & Budenberg, Limited, and that used by the city boiler 

 inspector. The only errors were in the initial setting of the needles. These in 

 all cases were corrected at a pressure of 20 pounds per square inch by actual 

 trial with a column of mercury. The damper was controlled by a lever passing 

 over a graduated segment. 



The chemical thermometers were of 550° C. capacity, and were calibrated by 

 the Physikalisch-Technische Reichsanslalt in Charlottenburg, Germany. The tem- 

 peratures of the flue gases were read from a high-grade mercury thermometer 

 which was calibrated from these. TTie usual U tiibe, or inverted siphon of 

 water, draft-gauge was used. One arm was open to the atmosphere and the 

 other, by means of the proper connections was inserted into the draft to be 

 tested. The difficulties of reading the gauge were reduced to a minimum by 

 the looking-glass scale. The latter was accurately divided into millimeters so 

 that the error of reading was not greater than a few units in the decimal. 

 The scale was movable, which greatly facilitated the reading of it. 



A Barms' continuous, surface condenser calorimeter was on hand during 

 several of the tests to determine the moisture in the steam. Steam nearly 

 always carries water with it and thus the boiler is credited with having evap- 

 orated more water than is really the case. However, the results recorded in 

 Table II have not been corrected for this since I was unable to determine tlie 

 factor for all. It will be seen from the following table that the boiler of this 

 Bureau produces steam which is verj' uniform in quality and as the results 



