HENR V BESSEMER. 203 



brick, originally used, was ordinarily burnt out in two charges 

 of twenty minutes each. 



Another important modification in the process related to the 

 kind of metal subjected to conversion, and its after treatment. 

 In his earliest experiments, Mr. Bessemer had, by accident, 

 made use of a pure Blaenavon iron ; but in his subsequent 

 trials, iron of an inferior quality had been subjected to con- 

 i'ersion, and the results were much less satisfactorj'. It was 

 found that the high temperature and copious supply of air blown 

 through the metal had failed to remove the sulphur and 

 phosphorus present in the original pig, and that the product was 

 an inferior metal. After a long series of experiments, Mr. 

 Bessemer at length found that the best results were obtained 

 from Swedish, Whitehaven, Haematite, Nova Scotian, or any 

 other comparatively pure iron, which was first melted in a 

 reverberatory furnace, before subjecting it to conversion, in 

 order to avoid contamination by the sulphur of the coal. 



Finally, to avoid the risk of spoiling the metal while under 

 conversion by the workmen stopping the blast at the wrong 

 time, Mr. Bessemer adopted the method of refining the whole 

 contents of the vessel by burning off the carbon, and then 

 introducing a quantity of fluid carburet of iron, containing the 

 exact measure of carbon required for the iron or steel to be 

 produced. 



When Mr. Bessemei', after great laDi.>nr and expense, had 

 brought his experiments to a satisfactory issue, and ascertained 

 that he could produce steel of a quantity and texture that could 

 be relied on with as much certainty as any other kind of metal, 

 he again brought the subject of his invention under the notice 

 of the trade ; but, strange to say, not the slightest interest was 

 now manifested in it The Bessemer process had been set 



