CHEMICAL EFFECTS OF PUDDLING. 133 



Sixth Sample, taken at 1 40 p.m. 



The reason why this sample was taken only five minutes 

 after the last sample, was that the mass in the furnace was 

 rapidly transforming itself into two distinct products, viz., the 

 scoria on the one hand and small globules of malleable iron on 

 the other. We attached some importance to this sample, as 

 the workman was on the point of beginning the balling or 

 agglommerating the globules of iron, so as to form large balls 

 of about 80 lbs. weight to be hammered and rolled out into 

 bars. Whilst the mass taken out for analysis was cooling, 

 small blue flames of oxide of carbon issued from it. These 

 were similar to those observed in Nos. 4 and 5, but were not 

 so abundant. 



The appearance of this sample was similar to the last 



one, with the exception that the scoria was not so intimately 



mixed with the globules of iron, and that these were larger 



and slightly welded together when hammered. The propor- 



of carbon and silicium were as follows : — 



First Analysis Fecond Analysis. 



Carbon 1 1160 



Siliciom . 0.167 0.160 MM 



When these figures are compared with those of the previous 

 analysis, it is interesting to observe that whilst the silicium 

 remains nearly stationary the carbon rapidly diminishes, for in 

 the five minutes which elapsed between the taking out of the 

 samples, there are 28 per cent, of the carbon burnt out. 

 This rapid decrease of carbon in the iron is maintained during 

 the remaining ten minutes of puddling. In fact, in one 

 quarter of an hour, viz., from 1 35 to I 50 the iron lost 50 

 per cent, of the carbon. 



Seventh Sample, taken at I 45 p.m. 

 This sample was obtained when the puddler had begun to 

 ball. The appearance of the sample, although similar to the 



