226 



BOILER TESTS. 



Results of Tests. Boiler No. 68. 



NOTE. The coal when fired contained 5 per cent, of moisture. 



The tests on Boiler No. 68 had for a principal object the 

 determination of the economy produced by the use of a flue 

 heater. The heater was in operation on Test No. 133, and it 

 was shut off on Test No. 134, the flue gases passing directly 

 from the boiler to the chimney. The use of this apparatus 

 secured an increase in the temperature of the water of 19(> 

 84 =112 degrees, and a reduction in the temperature of the 

 gases of 435 279= 15() degrees, resulting in an increase 

 in the evaporation per pound of coal amounting to 12.8 per 

 cent. 



Looking at the general performance of the boilers, when 

 worked without the heater, it appears that the result secured 

 is much inferior in point of economy to that obtained from the 



