92 ANNUAL OF SCIENTIFIC DISCOVERY. 



according to the usual method. If cast-iron be required, the cementa- 

 tion must be carried on until about 3 or 4 per cent, of carbon is ab- 

 sorbed, after which it is transferred to the blast-furnace, with a proper 

 ilux. Among the other claims of the patentee is one for the use of 

 spathose iron ores and " soft mine " as a flux, to supersede limestone, 

 the ore being first roasted, to drive out the carbonic acid, and then 

 mixed with other ores in such proportion that the lime contained in 

 the aggregate may bear a due proportion to the silica and alumina in 

 the other iron ores to be smelted. London Mining Journal, July 19. 



MANUFACTURE OF STEEL. 



MR. J. M. HEATH has taken out a patent for some improvements in 

 the manufacture of steel, which consist in the application of iron, pro- 

 duced from iron ores without being brought to the state of pig or cast 

 iron, to the manufacture of steel, the iron so produced being manufac- 

 tured by a process which renders it more suitable for conversion into 

 steel than the iron commonly used. The excellence of the steel de- 

 pends upon the freedom from mixture with impurities, which impuri- 

 ties can never be entirely removed from the metal by the operations in 

 use for converting the pig into malleable iron. Any pure ore or oxide 

 of iron, from which the extraneous matters can be easily separated, 

 may be used, but the magnetic ore is preferred. It is reduced to the 

 state of grains, or even of fine powder, to facilitate the separation of 

 the extraneous substances, after which the pure ore is to be reduced 

 to the metallic state by any of the well-known processes for depriving 

 the metal of oxygen, by acting upon it with carbon, or any reducing 

 agent, at a heat below that required to bring the metal to the fluid 

 state. The metallic product obtained in this way, when operating 

 upon the manufacturing scale, can never be absolutely free from all 

 impurity, and it always contains some portion of oxide of iron as it 

 comes from the process of deoxidation. To make perfect steel-iron, 

 however, the patentee takes the metallic product, as it comes from the 

 process of cementation or deoxidation, and mixes it with a small por- 

 tion of oxide, or chloride of manganese, and a certain portion of coal or 

 fir tar, or any cheap hydro-carbon or carbonaceous matter. The best 

 results are obtained from the mixture of from one to three pounds of 

 manganese and from one to two gallons of coal or other tar to each 

 hundred pounds of deoxidated ore. The mixture of granular iron, 

 tar, and manganese, resulting from this process, is heated in a suit- 

 able furnace, and when the iron is at a welding heat, it is removed 

 from the furnace, and subjected to compression in order to be formed 

 into a solid bloom by any of the usual processes. The bloom is then 

 to be re-heated and shingled, hammered, or rolled into bars in the 

 usual manner, after which it may be converted into steel by the well- 

 known processes, and will be found superior to that made from the 

 best iron hitherto procurable. Civil Engineer and Architect's Jour- 

 nal, July. 



At the meeting of the American Association, at New Haven, speci- 

 mens of iron were exhibited, made at Franklin, N. J., from Frank- 



