On the Manufacture of Bar Iron in India. 41 



has been regularly produced for six months together, with 

 none but natives to conduct the manipulation, after I had 

 superintended the requisite adjustments at first. 



14. The next improvement due to the French manufac- 

 turers, is a most important one. It is the introduction of 

 what is termed " gas-iron, a term which is now used in 

 " trade, and applied to a class of iron superior to coal-made 

 "iron, and almost equal for most purposes to charcoal-iron. 

 " Gas-iron, is iron manufactured with the gases lost in the 

 " blast furnaces, or with those arising from gasification of 

 •' combustibles of small value, or unfit in their natural state 

 " for working iron. This process originated in the works of 

 "Treveray, (Meuse,) belonging to Messrs. D'Andelarre and 

 " De Lisa, and is extremely important to works using vege- 

 " table fuel. Refining with charcoal has already become 

 " impossible in most of the French furnaces, on account of 

 " the competition of coal, and in a very short space of time it 

 " will be so with the rest. At present, coal bar-iron produc- 

 " ed from charcoal pig is little better than bad iron entirely 

 " manufactured in the English way, and fetches rather better 

 " price, but the difference in quality will not compensate for 

 " the great difference in price, and the cheaper article will 

 " exclude the other. The gas process on the other hand, if 

 " generally adopted, will save the old charcoal works, though 

 " it also effects a great saving with regard to coal ; an impor- 

 " tant saving in the gas process is the diminished loss in 

 " slag which is reduced one-half in the puddling and ball- 

 " ing furnace. In the Treveray process, the gases lost in 

 " the blast furnace, or the gases which have exhausted their 

 " physical and chemical influence on the bed of fusion, are 

 " collected and sent into the reverberatory ovens. These 

 " gases before being so used in the subsequent processes, 

 K are purified from the matter which they may contain in- 

 " jurious to the iron. This is effected by a very simple appa- 

 " ratus, and the pig-iron is brought into contact only with a 



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