Wootten.] -^l^ [March 3, 



the jiroduction of In-drogen and liydrocarbon gases, in addition to the 

 carbonic oxide usually formed. 



The l)lue tlanie of carbonic oxide is to a great extent replaced by that of 

 the hydrocarbons and hydrogen. The combustion of this fuel resembling 

 that of bituminous rather than anthracite coal; the flame extending occa- 

 sionally to a distance of over twenty feet, instead of as many inches, as is 

 the case in the combustion of carbonic oxide gas from ordinary anthracite 

 coal burned in the usual manner. 



The decomposition of the vapor causes a considerable reduction of 

 temperature in the furnace. This cooling eftect in the furnace does not, 

 however, result in a loss of heat, as the re-combustion of the hydrogen de- 

 rived from the decomposition of the vapor yields as much heat as was 

 absorbed in its formation. 



To insure the rapid and complete combustion of the fuel, and prevent 

 the formation of solid masses of clinker, it should be repeatedly stirred upon 

 the fire bed with a rabble-shaped tool. This stirring process is an import- 

 ant element in the successful use of the fuel under consideration, as it 

 serves to relieve the fire from the finely divided ash, which is thus exposed 

 to and carried by the draught over the bridge-wall or through the flues of 

 the boiler into the stack. 



The i)erforated fire-bed forms an essential feature of the device, inasmuch 

 as the loss of fuel through the grate during the stirring pi'ocess is thereby 

 greatly diminished, the average loss being less than two per cent, of the 

 coal put into the furnace, whilst the weight of the fuel used for steam 

 generation and stationary and locomotive l)oilcrs, is but slightly in ercess 

 of that which would be required of standard marketable sizes of prepared 

 coal when burned in the same furnace with the ordinary bar grate in the 

 usual manner. 



The perforations in the plate of the fire-bed, are made from three-eighths 

 to three-fourths of an inch in diameter, and from two to three inches from 

 centre to centre. 



Wrought iron is preferred for making the perforated fire beds, as that 

 material admits of the use of a much thinner' plate than cast iron, and con- 

 sequently there is less liability to obstruction of the air passages. 



The exhaust blast of the locomotive is altogether unsuited to the con- 

 sumption of the fuel under consideration, as by reason of its impulsive and 

 vigorous lifting action, it is impossible to maintain the fire in the compara- 

 tively quiescent condition requisite for favorable results with anthracite 

 coal dirt. 



The usual method of urging the fire by means of the exhaust steam has 

 therefore been entirely disiK-nsed with, and instead of discharging the ex- 

 haust steam directly into the atmosi^here, its heat is absorbed as far as ix)S- 

 sible, by passing it through tubular feed water heatere before allowing it to 

 escape. 



By this means, feed water is introduced to the boiler at a temperature in 

 excess of 212^ F. 



