U'lLLIAM SIEMENS, F.R.S, 6 1 



pig irons which constitute the bulk of our productions, and the 

 puddled iron cannot be brought to the condition of cast steel 

 except through the process of fusion. This fusion is accomplished 

 successfully in masses of from three to five tons on the open bed 

 of a regenerative gas furnace at the Landore Siemens-Steel 

 "Works and at other places. At the same works cast steel is also 

 produced, to a limited extent as yet, from iron ore which, being 

 operated upon in large masses, is reduced to the metallic state and 

 liquified by the aid of a certain proportion of pig metal. The 

 regenerative gas furnace, the application of which to glass houses, 

 to forges, &c., has made considerable progress, is unquestionably 

 well suited for these operations, because it combines an intensity 

 of heat limited only by the point of fusion of the most refractory 

 material, with extreme mildness of draught and chemical neutrality 

 of flame. 



These and other processes of recent origin tend towards the 

 production at a comparatively cheap rate of a very high class 

 material that must shortly supersede iron for almost all structural 

 purposes. As yet engineers hesitate, and very properly so, to con- 

 struct their bridges, their vessels, and their rolling stock of the 

 material produced by these processes, because no exhaustive ex- 

 periments have been published as yet fixing the limit to which they 

 may safely be loaded in extension, in compression, and in torsion, and 

 because no sufficient information has been obtained regarding the 

 tests by which their quality can best be ascertained. 



This great want is in a fair way of being supplied by the experi- 

 mental researches that have been carried on for some time at Her 

 Majesty's Dockyard at Woolwich under a committee appointed for 

 that purpose by the Institution of Civil Engineers. In the meantime 

 excellent service has been rendered by Mr. Kirkaldy in giving us, 

 in a perfectly reliable manner, the resisting power and ductility of 

 any sample of material which we wish to submit to his tests. 



The results of Mr. "Whitworth's experiments, tending to render 

 the hammer and the rolls partly unnecessary, by consolidating 

 cast steel while in a semi-fluid state, in strong iron moulds, by 

 hydraulic pressure, are looked upon with general interest. 



But, assuming that the new material has been reduced to the 

 utmost degree of uniformity and cheapness, and that its limits of 

 strength are fully ascertained, there remains still the task for the 



