president's address — SECTION B. 63 



was by that time universally understood — were not followed through, 

 by means of thermal calculations until at least a decade later (Hollway 

 for ores, 1878, Balling for mattes, 1885). 



As intimated, it was only the intellectual fillip given to pneumatic 

 smelting in general by that purely practical invention, the Bessemerising 

 of pig iron, in 1855, which stirred the ranks of the other metals into 

 imitative activity. In the case of iron the combustion of that metal 

 itself naturally did not form the object. However, the elimination 

 of certain impurities (sulphur, phosphorus) had engaged the attention 

 of the ironmasters ever since the invention of the puddling process, 

 and much was hoped for in this connection from the Bessemer process. 

 Still, the absence of anything positively analogous in copper or lead 

 smelting divested these particular efforts of pertinent or immediate 

 interest in the latter fields, and further time was lost. 



"With the rise of chemistry, i.e., with the fixation of the oxidation 

 theory as a foundation truth, coupled with the concurrent better com- 

 prehension of the fundamental chemical differences between pig iron, 

 steel, and ^vrought iron in terms of carbon, the pneumatic processes 

 first found a mitritive soil, out of which they could grow. Unfortu- 

 nately, the early attempts at applying any sort of rapid oxidation to 

 the refining of pig iron suffered from a partly chemical, partly 

 mechanical hindrance which arose from the erroneous appreciation 

 of the oxidising qualities, or rather, fuel-value of steam — a mistake 

 that was subsequently carried into copper-smelting, and is not extinct 

 even to-day. No doubt the greater ease and economy with which 

 steam of high pressure could be produced, as compared with com- 

 pressed air, suggested these attempts on the mechanical side. On 

 the chemical the motive was the expectation that the tremendous 

 heat- value of hydrogen would guarantee temperature, while the oxygen 

 would serve to remove the impurities. An associated chemical con- 

 sideration was that, since the waste of iron by the formation of cinder 

 is very considerable in puddling, an excess of air, or of oxygen, could 

 only be regarded as an evil. Consequently air was avoided, and every- 

 thing hoped from steam. This prejudice against superfluous air — 

 an evil of which the copper and lead smelters themselves had abmidant 

 practical evidence in their own work — doubtless fiu-ther retarded the 

 appreciation of the pneumatic principle in the case of the metals other 

 than iron. 



Revieiv of Early Sugqestions and Attempts in Iron before Bessemer. — 

 The history of the rapid oxidation idea as applied to iron-smelting, 

 though foreign to our subject, is still sufficiently closely related to it 

 in these its pristine days to warrant a brief digression for the purpose 

 of marking the course of development. 



The earliest positive conception on this subject, and thus virtually 

 the prime movement in this entire metallurgical department, seems 

 to have originated with Professor A. Guenyveau, of the Paris School 

 of Mines, who, in 1835, (a) advocated the employment of a mixture 



(a) Wedding, translation of Percy's " Iron and Steel," 1874. 



