METALS. 



4-.; 



with tin- iron. The final result of the opera- 

 tion is therefore, ;i JMIIV iron, hut under some 

 circumstances, not defined in the paper wo 

 quote I'roiii, Mccl i-, s:ii<l to In- produced. This 

 third process wo now huvo for refining 

 iron by the aid of soda-salts. "Which is the 

 be-! of the three wo iiniht leave manufacturers 

 to detoriuino. 



Incidentally, the authors mention a curious 

 alloy of sodium aud potassium. This is com- 

 j'oscd of 4 parts of the hitter with 2J part< of 

 the former; and it has exactly tho appearance 

 :.!i'l consistency of mercury, remaining liquid 

 at tho ordinary temperature of tho air. 



Russian Charcoal-Iron. Tho Russian char- 

 coal is still almost exclusively used for smelt- 

 ing, aud there is no question as to tho superior 

 quality of the iron thus produced. From re- 

 cent and carefully-collected information on the 

 subject, tho Builder ascertains that the pro- 

 duction of iron in Russia now requires tho 

 consumption of only 110 tons of charcoal to 

 100 tons of iron made. The lowest price of 

 lurch charcoal in Russia is 6s. 6d. per ton ; 8s. 

 2d. per ton is considered a cheap purchase ; 

 and 14s. 9d. per ton, and even more, is paid in 

 somo establishments. As this variation in 

 price, however, is almost all due to tho ex- 

 pense of land-carriage, there can be no doubt 

 that tho service of the great iron-works by 

 light railways, which can be laid and relaid 

 year after year to the portions of the forest 

 from which the supply is taken (on the princi- 

 ple of allowing from sixty to eighty years for 

 the regrowth of the timber), will keep down 

 the cost of charcoal for smelting something 

 below 10s. per ton of iron. 



Bessemer Metal. This variety of steel is 

 now cast in ingots of five tons each, free from 

 alloy, and fit to be used directly in tho manu- 

 facture of heavy articles. In such masses, how- 

 uver, defects in the form of bubbles are apt to 

 occur more often near the periphery of the 

 ingot than near its centre. A correspondent 

 of tho Mascliinen Constructeur says that ho 

 Las seen Bessemer metal used with great ad- 

 vantage for making the piston-rods of steam 

 hammers which were used for hammering 

 steel. Wrought-iron pistons and piston-rods 

 of tho same dimensions were used up in a 

 short time, by the change of the iron from a 

 fibrous to a granular structure, in consequence 

 of the repeated concussions to which they 

 were subjected. Bessemer metal has also been 

 used for locomotive axles with excellent re- 

 sults. Its use for this purpose^ as well as for 

 boiler-plates, is continually increasing in Eu- 

 rope. It has not been employed for either of 

 these purposes in England. Tho Engineering 

 and Mining Journal remarks that the fact that 

 it resists tho oxidizing effects of a flame much 

 better than wrought-iron is a strong argument 

 1'or its use in boilers. 



Malleable Cast-Iron. This article is tho 

 subject of a paper in the Journal of Applied 

 Chemistry, by Dr. Adolph Ott. The enormous 



flexibility of malleable iron, according to Mr. 



I:. Mall.-t, i- attributable to the fact that small 



crystalline scales of graphite are uniformly dis- 

 ci -in'natcd through the mass. The most rigid 

 materials become flexible when fibrous, or 

 scaly, crystals of different natures are distrib- 

 uted through them, as, for instance, the flex- 

 ible Indian sandstone with fibres of asbestos 

 running through its quartz-crystals, and the 

 itacolumite of Brazil, which contains mica 

 crystals associated with the quartz mass. The 

 specific gravity of malleable iron approaches 

 very nearly that of cast-iron. Morin and 

 Tresco have' shown that the elasticity of 

 malleable iron is considerably less than that 

 of tho most inferior wrought-iron. The ab- 

 solute power of resistance is indicated as be- 

 ing 35 kilogrammes per square metre. Thin 

 pieces, of a diameter not over one-quarter or 

 three-eighths of an inch, may be bent while 

 cold, without cracking; but they can rarely 

 bo restored to their original state without 

 being partly or altogether fractured. How- 

 ever, tho end of a rod may be forged till 

 red hot, without a break or crack being 

 produced ; thin plates may safely be ham- 

 mered into hollows, provided they are not 

 too deep. Malleable iron will bear rolling to a 

 small degree. All these manipulations bring 

 about a closer grain, and a fracture similar to 

 that of fine-grained steel-like iron. It may be 

 pretty well forged at alowl-ed heat, somewhat 

 above a cherry-red heat, but, in endeavoring to 

 beat it out, it tears and breaks to pieces. This 

 temperature, and that beneath a bright-yellow 

 heat, are those at which it may be best forged ; 

 but it is more than probable that various kinds 

 act differently under the same circumstances. 

 When hammered at yellow heat, malleable 

 iron falls to pieces, and large, not uniformly 

 cemented pieces, appear in the interior. With 

 respect to the fusing-point of this material, it 

 is a high one ; it lies above that of gray or 

 halved cast-iron, but probably not above that 

 of many sorts of white or hard cast-iron, and 

 certainly considerably below that of cast- 

 steel. 



Iron and Steel Crystals. Mr. Schott, of 

 Ilsenberg, has made many microscopical ex- 

 aminations of the structure of steel and iron, 

 lie maintains that all crystals of iron are of 

 the form of a double pyramid, the axis of 

 which is variable as compared with the size of 

 the base. Tho crystals of the coarser kinds are 

 of about twice the height of those of the finest 

 qualities. The more uniform the grain, tho 

 smaller the crystals, and the flatter the pyra- 

 mids, which form each single element, the 

 better is the quality, the greater is the cohesive 

 force, and the finer the surface of the iron. 

 These pyramids become flatter as the propor- 

 tion of carbon contained in the steel decreases. 

 Consequently, in cast-iron and in the crudest 

 kinds of hard steel, the crystals approach 

 more the cubical form, from which the octa- 

 hedron proper is derived, and the opposite ex- 



