:HE STEAM ENGINE. 



of fuel obtained by the complete consumption of smoke. Various 

 methods, however, may be adopted by which fuel may be supplied 

 to the grate without opening the fire-doors, and without disturbing 

 the supply of air to the fire. A hopper built into the front of the 

 furnace, with a moveable bottom or valve, by which coals may be 

 allowed to drop in from time to time upon the front of the grate, 

 would accomplish this. 



In order to secure the combustion of the gases evolved from the 

 coals placed in the front of the grate, it is necessary that a supply 

 of atmospheric air should be admitted with them over the burning 

 fuel. This is effected by small apertures or regulators, provided 

 in the fire-doors, governed by sliding plates, by which they may 

 be opened or closed to any required extent. 





