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And first, what is steel? How was it made and manipulated a few years since? How is it made now?
As to what it is, I suppose the text-book would tell us that it is the element iron united to a small proportion of the element carbon, and is a material which in these respects lies between wrought iron and cast iron. In practice, no doubt, there are commonly other constituents, such as manganese, for example, but for the purposes of to-night it will suffice that we look upon steel as being composed of iron and of carbon.
It is not so many years since, that steel was made by the cementation process, that is by heating bars of wrought iron in contact with charcoal, until they had become sufficiently carbonised. These bars were, from the appearance of their surface, known as blister steel; they might either be worked from their then condition, or they might be broken into fragments, selected for degree of carbonisation, then be put into a crucible and melted to produce cast steel. Each crucible contained but a few pounds weight, and the resulting ingot, cast in a metal mould, was rarely heavier than the charge of one crucible, although occasionally the contents of more than one crucible were used, to make an exceptionally large ingot. The ingot having been drawn out, the result was the cast-steel bar used for cutlery and for engineers' chisels and turning tools, a material that was produced in quantities stated in pounds, and that was sold at so much a pound, and was an article of luxury.
I do not wish to be trapped into repeating to you to-night my lecture of 1877 on the Future of Steel, and I will therefore pass over the attempts to make steel by the puddling process, by the Chenot process, and by the Uchatius process; neither will I say anything about that important branch of industry, steel casting, but I will come at once to the three modes by which in these days, ingots for large forgings are produced.
The crucible plan (the oldest mode, and one which still survives, although I believe it is rapidly dying out) is to employ as many hundreds of crucibles as the size of the ingot needs,
