SOME REMARKS ON HEATING. 



299 



A. The furnace door. 



B. The ash pit door. 



C. The dumb plate. 



D. and E. Soot doors. Another soot door (on the opposite side to E.) is supposed to 

 be removed. 



F. F. The upper and lower flues, which are alike on both sides of the boiler. 



G. .'\n iron flue plate to separate the lower from the upper flue, which is built into the 

 brickwork. 



H. A lirick separation of the flue on the top of the boiler. 



J. The damper in the chimney. 



K. and L. Two fire clay lumps, placed close to the back of the Ijoiler. The space be- 

 tween tliese is from .3i to 4i nches, according to the sizeoftlie boiler and the height of 

 the cliimney. This opening is the only passage for the flame and smoke from the furnace 

 into the flues. 



Y 2 



