ON THE ADVANTAGEOUS USE OF A GASEOUS ESCAPE. 83 
ployed, and from its igniting at a lower temperature, greatly assist in the 
operations of the gas furnace ; and therefore I believe the fuel put into the 
blast-furnace would, with such arrangements, not only by the combustion 
of its solid part, at and near the tuyéres, smelt the pig-iron from the ore, but 
by the mere passage of these vapours, heat the blast, raise the steam, and 
finally, by the entire combustion of the gases, supply fuel for the forge and mill, 
and thus complete the whole conversion from the ores to malleable iron, by 
the consumption of about 2 tons of fuel, instead of using. 6 tons or there- 
abouts as at present. It cannot’be doubted that the air-furnace is a most 
imperfect instrument in metallurgy: a large proportion of the fuel is unprofit- 
- ably converted therein into combustible gases, which pass unburnt out of the 
chimney. It requires indeed a very large drawback from the effect of the fuel 
used in air-furnaces, to account for how I| have attained such superior results, 
_ by merely passing one-half of the gaseous escape unconsumed through a boiler 
on one side of my No. 9 furnace, and through a heating stove on the other. 
_ The difficulty that would remain in carrying out fully the utilization of the 
whole power of the fuel put into the furnace, would be the management of 
the gas-furnace. 1 regret I have not had opportunities of personally witness- 
_ ing the use of gas-furnaces, consuming the escape from blast-furnaces, for the 
purposes of the processes of the forge and mill, such being only practised 
abroad, where the dearness of fuel has induced persistence and perseverance 
in the application ; I have however witnessed a gas-furnace in successful opera- 
tion at Ynyscedwyn, under the direction of the patentee, Mr. Detmold. In 
this case, the gas was not however derived from the blast-furnace, but was 
_ generated in a sort of double furnace, in which the combustible gases are ge- 
nerated by a blast of air injected into the ash-pit, whence it passes through the 
coal in the grate, whilst the combustible gases thus produced are consumed by 
forcing amidst them in their passage over the fire-bridge, heated and com- 
_ pressed atmospheric air supplied in numerous small streams. 
_ Mr. Detmold had successfully introduced this description of furnace for 
forge and mill purposes into the anthracite districts of the United States, 
where from a deficiency of flame this fuel could not be used for boiling and 
_ puddling in the usual reverberatory furnaces, and he came over to this country 
to introduce his improvements here. The gas-furnace tried at Ynyscedwyn was 
' for the purpose of refining pig-iron, or converting it into what is technically 
: called metal, it being a desideratum to refine with anthracite coal, which from 
_ its great density we are unable todo. The heat produced was very great, 
yet by means of water-breasts, and other contrivances, the furnace stood 
' pretty well. The iron was speedily converted into metal, which proved on 
trial to be of good quality ; and the loss of yield was much less than in the 
_ refinery process at present used ; but the metal had a dull appearance instead 
of the silvery appearance, by which its good quality is generally judged; and 
_ 8 a greater part of the anthracite metal is exported to distant markets abroad, 
this difficulty caused the process not to be pursued. It appears to me probable, 
from the difficulty there will be to use anthracite coal in puddling, boiling 
_ and balling, on account of the absence therein of the constituents that make 
the protecting flame necessary in these processes in reverberatory furnaces, 
“that the gas-furnace will be introduced into use in this country in the 
anthracite districts, when the manufacturers of iron with this fuel feel the 
necessity of extending beyond the make of pig-iron. I may therefore, at 
Some subsequent meeting of the British Association, have to detail the results 
this application at Ystalyfera. At present, 1 shall carefully proceed to 
apply the heating power of the gaseous escape fully to the boilers, as 1 have 
‘done to the stoves, and shall also endeavour to calcine the mines in the same 
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