SIR WILLIAM SIEMENS, F.K.S. 281 



correct, it followed that a pig metal, rich in carbon and in silicon, 

 would give greater yields than a metal containing those foreign 

 substances in smaller proportion, or that grey pig metal would 

 produce larger yields than white iron. The report also made 

 mention of the possible application of this furnace to what was 

 called the " Siemens-Martin " process. He could not fall in with that 

 view. It would be very difficult to realise such a temperature in 

 a rotating furnace as was required for carrying out a process in 

 which they had five or six tons of almost pure iron in a fluid con- 

 dition iron containing about one-tenth per cent, of carbon. 

 Another fatal circumstance would be that the lining of the Danks 

 furnace was composed of oxides of metal, and in the presence of 

 oxides of metal they could not have fluid mild steel. The steel 

 would immediately part with its small percentage of carbon, and 

 become wrought metal. Therefore, it could not be applied, he felt 

 certain, to carrying out that process. But he might remark that 

 some years ago his attention had been directed towards a 

 rotating apparatus, not for puddling, but for accomplishing just the 

 reverse operation that of reducing oxides into the metallic con- 

 dition. He had steadily followed out those experiments, and before 

 long he might have the pleasure of bringing them before the 

 Institution. Before sitting down he wished to express that he 

 was entirely satisfied with the able, and evidently strictly impartial, 

 reports which they had received. 



Mr. I. Lotvthian Bell said he should like to put one question to 

 Mr. Siemens, who mentioned that the richer the pig iron was in 

 silicon, the better the yields. That, he supposed, he ascribed 

 to the action of silicon upon the oxide of iron. But he (the 

 speaker) believed a very general impression prevailed amongst 

 puddlers that that could only be true to a moderate extent ; 

 because the silicon, by taking the oxygen, was changed into 

 silica, and that, not being able to exist in a puddling furnace in 

 its uncombined state, combined with oxide of iron, and was thereby 

 a source of waste. 



Mr. Siemens in reply stated that with regard to the carbon, the 

 result had been proved in the most conclusive manner, by ex- 

 periments which he himself had made in the regenerative gas- 

 puddling furnace. The richer the pig iron was in carbon, the 

 greater was the yield of wrought metal produced. The same 



