1840.] 



On Indian Iron and Steel* 



187 



procured from a larger quantity. When the fusion has been perfect, 

 the top of the cake is covered with striae, radiating from the centre, 

 but without any holes or rough projections on it t when the fusion has 

 been less perfect, the surface of the cake has a honey-combed appear- 

 ance, caused probably by particles of scorise andjunreduced oxide in the 

 bar-iron, and often contains projecting lumps of iron still in the 

 malleable state. 



The crucibles are formed of a red loam, which is very refractor)'', 

 mixed with a large quantity of charred husk of rice ; they are made 

 by taking a lump of the tempered clay in one hand, and giving it a 

 rotatory motion, while it is hollowed out by the fingers of the other 

 hand : each crucible serves only for one operation. 



The natives prepare the cakes of steel for being drawn into bars 

 by annealing them for several hours in a charcoal fire, actuated by 

 bellows, the current of air from which is made to play upon the cakes 

 while turned over before it at a heat just short of that sufficient 

 to melt them. It appears from this, that in order to insure the fusion 

 of the contents of the crucible, it is found necessary to employ a 

 larger dose of carbon than is required to form the hardest steel, and 

 that this excess is afterwards got rid of by annealing the cakes before 

 a current of air at a high heat, the oxygen of the air combining with 

 and carrying off the excess of carbon in the gaseous form : without 

 this operation none of the cakes would stand drawing into bars without 

 breaking. 



The only fuel employed by the natives of India throughout the 

 different stages of iron and steel making is wood charcoal. The 

 magnetic oxide of iron, when separated trom the quartz with which 

 it is naturally combined in the ore from which the wootz steel is made, 

 consists of 72 per cent, of iron and 28 of oxygen. The native method 

 of smelting the ore is so exceedingly imperfect, that the produce 

 from their furnaces in bar-iron does not average more than fifteen 

 per cent. 



When specimens of Indian steel were first examined by chemists 

 in England, they were quite unable to discover the process by which 

 it had been manufactured. The late Dr. Pearson published an account 

 of his examination of this substance in the seventeenth volume of 

 the Philosophical Transactions, and the result of his observations is 

 in these words : " We may without risk conclude that it is made direct- 

 ly from the ore, and consequently that it has never been in the state 

 of wrought-iron." Dr. Buchanan's Travels in the South of India were 

 published in the year 1807 : they contain a very minute and correct 

 account of the native processes of smelting iron and making it into 

 steel, illustrated by engravings. Dr. Heyne's Tracts on India, were 



