Chemistry and Physics. 



411 



shapes required, provided that we increase the size and power of our ma- 

 chinery to the extent necessary to deal with such large masses of metal, 

 A few minutes' reflection will show the great anomaly presented by the 

 scale on which the consecutive processes of iron-making are at present 

 carried on. The little furnaces originally used for smelting ore have from 

 time to time increased in size, until they have assumed colossal propor- 

 tions, and are made to operate on 200 or 300 tons of materials at a time, 

 giving out ten tons of fluid metal at a single run. The manufacturer has 

 thus gone on increasing the size of his smelting furnaces, and adapting 

 to their use the blast apparatus of the requisite proportions, and has by 

 this means lessened the cost of production in every way ; his large fur- 

 naces require a great deal less labor to produce a given weight of iron 

 than would have been required to produce it with a dozen furnaces, and 

 in like manner he diminishes his cost of fuel-blast and repairs, while he 

 insures a uniformity in the result that never could have been arrived at 

 by the use of a multiplicity of small furnaces. While the manufacturer 

 has shown himself fully alive to these advantages, he has still been under 

 the necessity of leaving the succeeding operations to be carried out on a 

 scale wholly at variance with the principles he has found so advantageous 

 in the smelting department. It is true that hitherto no better method 

 was known than the puddling process, in which from 400 to 500 weight 

 of iron is all that can be operated upon at a time, and even this small 

 quantity is divided into homoeopathic doses of some seventy or eighty 

 pounds, each of which is moulded and fashioned by human labor, care- 

 fully watched and tended in the furnace, and removed therefrom one at 

 a time, to be carefully manipulated and squeezed into form. 



When we consider the vast extent of the manufacture, and the gigan- 

 tic scale on which the early stages of the process are conducted, it is as- 

 tonishing that no effort should have been made to raise the after-processes 

 somewhat nearer to a level commensurate with the preceding ones, 

 and thus rescue the trade from the trammels which have so long sur- 

 rounded it. 



Before concluding these remarks I beg to call your attention to an im- 

 portant fact connected with the new process, which affords peculiar facili- 

 ties for the manufacture of cast-steel. 



At that stage of the process immediately following the boil, the whole 

 of the crude iron has passed into the condition of cast-steel of ordinary 

 quality ; by the continuation of the process the steel so produced grad- 

 ually loses its small remaining portion of carbon, and passes successively 

 from hard to soft steel, and from soft steel to steely iron, and eventually 

 to very soft iron ; hence, at a certain period of the process, any quality 

 of metal may be obtained ; there is one in particular which, by way of 

 distinction, I call semi-steel, being in hardness about mid-way between 

 ordinary cast-steel and soft malleable iron. This metal possesses the ad- 

 vantage of much greater tensile strength than soft iron ; it is also more 

 elastic, and does not readily take a permanent set, while it is much harder, 

 and is not worn or indented so easily as soft iron ; at the same time it is 

 not so brittle or hard to work as ordinary cast-steel. These qualities ren- 

 der it eminently well adapted to purposes where lightness and strength 

 are specially required, or where there is much wear, as in the case of 



