78 



BOILEE TESTS. 



that this was about the maximum which, under the unfavorable 

 circumstances noted, could be obtained. The increased 

 amount of power obtained was accompanied by an increase in 

 the amount of ash, due probabty to a greater amount of coal 

 wasted by dropping through the grates. It is seen that as the 

 power increases, the temperature of the escaping gases becomes 

 higher, reaching a maximum in the last test of 407 degrees. 

 This is not a high figure for the amount of power developed* 

 and it indicates that the special arrangement of tubes secured 

 a more thorough absorption of the heat than would otherwise 



occur. 



Boiler No. 5. 



Kind of boiler, ...... Horizontal return tubular. 



Number used, ....... One. 



Horse-power, (basis 12 square feet), . . Fifty-four. 



Age, ........ Several years. 



Boiler No. 5 is a horizontal 

 return tubular boiler, set in 

 brick-work in the manner shown 

 in the following cuts. It is the 

 end boiler of a plant of the same 

 kind, and the boiler next to it 

 was in operation during the pro- 

 gress of the tests. The boiler 

 is an old one, and the heating 



surfaces are somewhat covered 

 BOILER No. 5, CROSS SECTION 



THROUGH FURNACES. with scale. 



BOILER No. 5, LONGITUDINAL SECTION. 



