STEEL.— Bessemer Process. 85!)

sary during the whole time that the crude metal wasbeing run into the vessel, in order to prevent itsentering the twyers. These disadvantages were ofthemselves well nigh fatal to the commercial workingof the process. To remedy these defects, Bessemerdesigned that peculiar-shaped vessel mounted onaxes, now so well known as the Bessemer “convertor.”This vessel has numerous fixed twyers evenly dis-tributed over the bottom of it, and the peculiar formof the vessel allows it to be put in such a positionthat the crude metal may be run into it, withoutrising up to and covering the twyers ; so that afterall the charge has been run in, it may be turnedquickly into an upright position, when the twyerswill become immersed below the fluid, and the wholecharge be thus operated upon simultaneously, insteadof portions of it being blown from the first com-mencement to run in the metal, as was the case withthe fixed vessel before described; and so in likemanner, at the desired moment, the process is madeto cease by a reverse movement of the vessel, whichbrings the orifices of the twyers again above thelevel of the metal.

This movement of the vessel on axes, and itspeculiar form, afford also great facilities for gettingrid of the fuel used in the first place to heat it, andfor discharging the converted metal and the scoriaafter the operation ; it also enables the workmen toobtain safe and ready access to the twyers, whilethe shower of cinders and flame emitted during theoperation is directed into a chimney, and conveyedaway.

The extreme irregularity in the weight to be movedduring the different positions which the vessel oc-cupies, and the difficulty of conveying motive powerto it by the ordinary appliances of drums and straps,&c., is entirely overcome by the application of ahydraulic cylinder, the piston-rod of which is joinedto a rack, and gears into a toothed wheel fixed onthe axis of the convertor, the power being controlledby a lad stationed at a convenient distance from theheat and splashes of the apparatus. Novel andimportant as is the invention of converting crudemolten iron into steel in a few minutes, withouthuman skill or manipulation, it is perhaps more thanequalled by the novelty and ingenuity displayed indevising an apparatus so well adapted to carry outthe peculiar requirements of the original intentionson a grand commercial scale.

It is curious to observe how greatly accidentalcircumstances sometimes modify the course pursued,and the results obtained in experimental research.The quality of pig iron which Bessemer happenedto purchase for his early experiment contained solittle sulphur and phosphorus, that most encouragingresults were obtained; indeed, some of the firstexperimental ingots made by him in London weresuccessfully rolled into flanged rails at Dowlais,from ingots 10 inohes square, without either theemployment of spiegeleisen or the process of ham-mering previous to passing them through the rolls.This early success caused Bessemer to very muchunderrate the injurious effects of sulphur and phos-

phorus, so plentifully found in common pig iron ;indeed, he appears to have taken it for granted thatthese elements would all disappear under the influ-ence of the excessive temperature generated in hisprocess.

Bessemer rightly divined that by blowing air intothe molten metal the carbon and silicon would boeliminated ; and he found that by the combustion ofthese elements alone, the metal would be raised toa temperature sufficient to maintain malleable ironin a state of perfect fluidity; but he was entirely inerror in supposing that the sulphur and phosphoruswould be driven off by excess of temperature, andhence all attempts to convert the lower qualities ofpig iron by his process has hitherto failed.

The success attained up to this time was veryremarkable ; and there is no wonder that the read-ing of the paper by Bessemer at the Cheltenham meeting of the British Association on 13th August,

1856, which he described as “ On the Manufactureof Malleable Iron and Steel without Fuel,” produceda startling effect upon those engaged in the manu-facture, and that several of those most largelyinterested were anxious to secure the right to makeiron and steel in such an apparently economicalmanner. Indeed, such was the anxiety of a fewleading men to acquire an interest in the patent,that within twenty-five days of the reading of thepaper “licenses to manufacture malleable iron underthe patent were purchased by iron-masters to theextent of £25,000.”

An unprejudiced observer, reading the paper ofBessemer at the present time, cannot but be struckwith the clear manner in which he had grasped thesubject, and a perusal of the whole paper will wellrepay the reader.

The following analysis of the first Bessemer steelrail, kindly furnished by E. Williams, will be readwith interest. The carbon is much lower, but inother respects it is remarkably like an analysis ofsteel made by the Heaton process, analyzed bySnelus, and recorded in the Iron and Steel Insti-tute Proceedings, and is in fact a phosphorus steel.Williams states that “the steel rolled uncommonlywell.”

Analysis by ,T. E. Stead of the first Bessemer steelrail rolled at Dowlais in 1858: —

Iron,. 99-300

Carbon, . *081

Manganese, . trace.

Silicon,. trace.

Sulphur,. *139

Phosphorus,. *446

Copper,. none.

99-966

Although Bessemer had succeeded thus early inproducing material of most remarkable quality, itmust be admitted that there was still a degree ofuncertainty in stopping the operation at the rightpoint to produce the harder qualities of steel; whileif the softer varieties, approaching in character towrought iron, were to bo made, it became necessarystill to employ the finer varieties of Swedish east