TILTING OF STEEL. 



il weight ; and llie wiight of the charcoal which difap- 

 1 wasf>7,'a fxr cent. The metallic button was very 

 iiiglily cirlionatcd, aiid apparently formed an entire mafs of 

 carburet. 



One-ninth of charcoal produced a fuper-carbonated but- 

 ton of crude iron, rather inferior to the preceding in point 

 of carbonization : its furface was fmooth, and of a dull 

 lead-colour, entirely free from the ufual Ihining fpecks of 

 carburet, which ver)- rich crude iron contains upon its fur- 

 face. It had gained equ.il to -j^tli in weight by the fuiion ; 

 and the lofs in charcoal was 8o per cent. 



When treated in the fame manner with Tith of its weight 

 of charcoal, the iron gained weight equal to Vt parts : and 

 Kj.5 per cent, of the charcoal difappeared in the procefs. 

 The metallic button pofTcfTed an uniformly fmooth furface, 

 partially covered with carburet. 



One-tifteenth part of charcoal, expofcd with the iron to a 

 heat fufficient to melt it, was all loft ; tlie metal gaii;ed Vjtij 

 in weight, which was exadly half the weight of charcoal loil. 

 The furface of the button was not carbonated, as the fore- 

 going experiments : the colour was blueifh -black, fmooth in 

 Uie centre, but a httle oxydated towards the edges. The 

 frafture was that of clofe dark -grey crude iron ; the cryftals 

 much clofer and more minute than in the preceding experi- 

 ments. Its quality was fuch as mauufafturers term No. 2. 

 grey melting pig-iron. 



When only ,', th part of charcoal was employed, none of 

 which remained after the fufion, the iron gained V^ parts in 

 weight : a fmall portion of amber-coloured glafs was found 

 round the edges of the button. The frafture of the metal 

 was fmooth filvery-white, occafionally ftudded with car- 

 bonaceous fpecks in form of fmall grains : it exaftly re- 

 fembled mottled pig-iron. ' 



With iVth part of charcoal, the metal gained -^ parts in 

 weight, the whole of the charcoal difappearing. The upper 

 furface of the button was fmooth, but the under confider- 

 ably pitted. The concaves were chequered with the rude 

 cryftallization peculiar to caft-iron. Its frafture was bright 

 filvery -white, deftitute of grain, and exhibiting a very perfect 

 ftreaky cryftallization (lightly radiated : its refemblance 

 was ftrikingly fimilar to that of highly-blown crude iron, 

 prepared in the finery for making malleable iron. 



A piece of Swedifh iron was placed in -.'ath its weight 

 of charcoal ; the fufion of the mixture produced a metallic 

 button weighing -^^ parts more than the iron employed, 

 which increafe is not quite a quarter of the lofs in charcoal, 

 which wholly difappeared in the experiment. The upper 

 furface of the button was fmooth without configuration, 

 but the under furface was uneven, and covered with minute 

 but perfeA cryftallization ; its frafture was blueilh filvery- 

 white, compofed of flat dazzling cryftals, proceeding in lines 

 from a centre to the edges of the button. Here it was 

 evident, that from the fmall proportion of carbon combined 

 with the iron, it was found to aftume the earlieft ftage of 

 granulation approaching to the ftate of fteel. The briUiant 

 concretions obfervable in the furface of the button were too 

 indiftinA and flat for fteel capable of bearing the hammer. 



When the proportion of the charcoal was reduced to 

 ^■gth of the iron, its confequent increafe was but xTjcth 

 part. The upper furface of the button was fmooth, with 

 9 faint imprclTion of a chequered cryftallization : the under 

 furface poflefted fome large pits fimilarly though more per- 

 feftly cryftallized ; the frafture was one fhade of blue 

 beyond the laft experiment, A regular granulated furface, 

 compofed of flat oblong cryftals, was obfervable, ftill too 

 indiftin(5l and too much on edge for workable fteel. 



With only ^'^th of the weight of charcoal, the button 

 was deficieijt ^ J ^th part of its weight originally ufed, ye^ 



the whole of the charcoal was loft. Tlie furfaces of tiii« 

 button were uniformly fmooth ; the frafture denfe, and 

 difplaying a grain peculiar to highly faturated bliftcred 

 fteel. When put under the hammer with a low red heat, it 

 withftood a few blows, but afterwards parted. 



Charcoal ^ : the metallic button weighed lefs than 



the iron employed. Its furface was wavy and cryftallized : 

 the under furface was rough, and contained one large pit ae- 

 curately cryftallized : the frafture was regularly granulated, 

 fmall but dillinft, and of a light blueilh colour. The cryftals, 

 though dillinft, were not fo prominent as thofe of eafy draw- 

 ing caft-fteel ; it however hammered with the ufual degree of 

 caution neceftary in the working of caft-fteel. The bar of 

 fteel formed from the button w as very proper for file-making, 

 and other purpofes requiring highly converted fteel. 



The proportion was reduced to m^jth part the weight 



of iron : the produce was lefs than the original weight 



of iron. The furface of the button was fmooth, without 

 cryftals : the under furface rough, and poffeffed of one 

 large pit in the centre, faintly marked with the ufual cryf- 

 talline appearance. The frafture prefented regular light- 

 blue grains, diftinft and more prominent than in the laft ex- 

 periment. One half of this button was drawn into a neat 

 fquare bar, and proved excellent fteel. One end of it, being 

 loofe and flialed, welded tolerably well, and hardened after- 

 wai-ds with a low heat. From its quality, it feemed adapted 

 for manufafturing penknives, razors, &c. pofiefGng neither 

 the extremes of hai-dnefs nor foftnefs. 



Mr. Mufliet continued this feries of experiments till the 

 proportion of charcoal became fo fmall as ^T,th part ; and 

 he gives the following conclufions, deduced from the refults. 



Parts bj 

 Weight. 

 Iron femi-fteelified is made with charcoal -pfj. 



Soft caft-fteel, capable of welding, with - -r^ 

 Caft-fteel for common purpofes, with - ttt^ 



Caft-fteel requiring more hardnefs, with - -g-V 



Steel capable of ftanding a few blows but quite 1 , 

 unfit for drawing, - - - S ^^ 



The firft approach to a fteely granulated! , 

 frafture, is from - - - J ^"^ 



White caft-iron -jV 



Mottled crude iron ... - ./^ 



Carbonated crude iron ... _^ 



Super-carbonated crude iron - - ^^, or 



when any greater quantity is combined with it. 



In the above experiments it will be feen, that when more 

 than ^'gth part of charcoal is employed, the weight of the 

 produce is increafed ; but when lefs than V^th part is ufed, 

 a lofs is experienced proportioned to the diminution of the 

 carbon. The increafe of weight in the iron is by no means 

 equal to the lofs in the charcoal, never exceeding the half 

 thereof ; but this is accounted for in other experiments maae 

 by Mr. Muftiet, where charcoal was found to be tranfmitted 

 through clofe crucibles in a high degree of heat. 



The French chemifts made a direft experiment to prove 

 that the diamond is really carbon in a cryftallized ftate. By 

 inclofing a fmall diamond in a piece of malleable iron, and 

 melting this in a clofe crucible, it was found to be con- 

 verted into fteel, and the diamond had difappeared. 



The manufafture of natural Jleel is carried on in Germany, 

 and Swedenborgius gives us the following account of the 

 method ufed in Dalecarlia for making fteel firom caft-iron. 



Thq 



to-, 



