BOILER No. 2. 



71 



sisted, in part, of a row of pipes, connected together with 

 return bends, placed behind the bridge wall, and, in part, of a 

 cylinder, which was located in the place ordinarily occupied by 

 the bridge wall at the back end of the grate. The total area 

 of the surface thus introduced amounted to 60 square feet. 

 The feed water on leaving the pump was first discharged into 

 the pipes and bridge Avail cylinder. After circulating through 

 these, it was discharged into the steam space at the top of the 

 boiler. At the time of the introduction of these pipes, the 

 bridge wall at the rear 

 end of the boiler was 

 removed altogether, and 

 the opening above the 

 wall at the front was 

 increased. A change was 

 also made in the speed 

 of the blower, which, on 

 the first test, was at times 

 too low for the desired 



draught. 



BOILER No. 2, CROSS SECTION THROUGH FURNACE. 



BOILER No. 2, LONGITUDINAL SECTION. 



