. A treatise on steel : comprising its theory, metallurgy, properties, practical working, and use. n combining agood draft with a complete surrounding of the cruci-bles by a powerful and constant flame. Experimentsmade on a large scale at St. Etienne and at Cham-bon, had to be Fig. 11. 285. The steel of cementation, broken into smallpieces, is introduced into the pots through the fun-nel or charger here represented. This charger isso constructed that it will go into the crucible, whichwill be thus protected against breaking by the piecesof steel thrown into it. When the charge is m
. A treatise on steel : comprising its theory, metallurgy, properties, practical working, and use. n combining agood draft with a complete surrounding of the cruci-bles by a powerful and constant flame. Experimentsmade on a large scale at St. Etienne and at Cham-bon, had to be Fig. 11. 285. The steel of cementation, broken into smallpieces, is introduced into the pots through the fun-nel or charger here represented. This charger isso constructed that it will go into the crucible, whichwill be thus protected against breaking by the piecesof steel thrown into it. When the charge is made,the pot is covered with a lid,the necessary quantity of freshfuel is added, and the processis allowed to go on until thesteel is completely fused, whichtakes place after a length oftime learned by practice. However, the length of theoperation varies with the sizeof the crucibles; in some Eng-lish works it is done in twohours; in some, six hours arerequired; in others, three hoursonly are necessary. It being important that atmospheric air shouldnot penetrate into the pots, they are properly. 1 Siemens gas furnaces are well spoken of.— Trans. 184 on steel. covered. For this purpose, the top of the pot hasbeen ground over a flat stone, so that the lid orcover fits it exactly. In many steel works, the clayfor the lids is not very refractory, in order that?under the intense heat, it may become somewhatvitrified and adhere to the top of the pots, thus com-pletely preventing the entrance of air. During the operation, the workman watches thefire continually, so as to add fuel if that in the fur-nace is sinking; but this rarely occurs, if the fuelhas been broken into pieces about the size of an generally takes place when the pieces areof unequal size. When it is thought the operationis complete, the furnace is uncovered and left openfor a few minutes, till the lids of the pots have cooledsomewhat, that they may be easily removed. Bywaiting too long, they would
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Keywords: ., bookcentury1800, bookdecade1860, bookidtreatiseonst, bookyear1868
