WILLIAM SIEMENS, F.R.S. 451 



to the first of these two questions, as ho had to most questions re- 

 iranling the production of steel in large masses by his process, 

 lie miirht say that he had himself occasionally given attention to 

 it also, but he had not been bold enough to resort to the mechani- 

 stirrer, which Sir Henry Bessemer had conceived, and which 

 now practically being carried out, as it appeared, with advan- 

 tage. He had tried sometimes to produce agitation by resorting 

 to what the copper-smelters called " polling," that was, putting 

 into the ladle poles of dried wood, which made a considerable 

 agitation without disturbing the chemical condition of the metal. 

 No doubt all these means were very beneficial, and he was not the 

 least surprised to hear of the good results which had been obtained. 

 The second question was one involving greater difficulty, because 

 the results placed before them by Mr. Snelus proved, what they had 

 already had occasion to observe, especially with regard to the plates 

 of the Livadia's boilers, that there was chemical change going on in 

 the metal when it first consolidated. The portion which first 

 solidified seemed to take with it such admixtures as manganese, 

 phosphorus, and carbon even, often leaving the metal in the centre 

 of a different composition. The only way to counteract such 

 action within the ingot mould would be that of very rapid cooling. 

 That would be attended with great difficulty, and particularly if 

 they dealt with very large moulds. But he believed he had 

 observed that it depended also upon the time which was allowed 

 to the fluid metal, when thoroughly mixed, to stand before it was 

 poured into the mould. There was such a thing as imperfect and 

 perfect chemical admixture. To use a popular illustration, they 

 might pump carbonic acid into water and make soda-water, but if 

 they used it immediately after it was made, they might just as well 

 save themselves the trouble of forcing the carbonic acid into the 

 water, because it came out instantly. If they had a second bottle 

 made in the same manner, and it were left for a week, they would 

 find a better chemical combination ; but if they left it for three 

 months, they would have the carbonic acid retained by the water 

 for a very considerable length of time after being poured out. He 

 had observed that considerable benefit accrued to the steel if, after 

 it had been poured into the ladle, it were allowed to remain there 

 under the protecting covering of slag to prevent decrease of 

 temperature. The objection to this mode of proceeding was, that 



G O 2 



