METALLURGY. 



531 



is detrimental to the soundness of the fabric, is 

 wholly obviated in it. 



BESSEMEB STEEL IN THE UNITED STATES. 

 From the reports of the companies owning 

 the fourteen completed Bessemer- steel works 

 which were in operation in the United States 

 in 1882, it appears that 1,696,450 net tons of 

 steel ingots and 1,253,129 net tons of steel rails 

 were produced during the year. These figures 

 represent an increase in production of 10 per 

 cent in ingots and of 6 per cent in rails over 

 the production of the same mills in 1881. The 

 rate of increase is much smaller than had 

 been made before for several years. Thus, 

 the increase in the production of ingots in 

 1881 was 28 per cent over that of 1880, while 

 that of the latter year was 30 per cent over 

 that of 1879. The figures representing the 

 production of rails do not cover the total pro- 

 duction of steel rails in the United States, as 

 some rails were rolled in 1882 from import- 

 ed steel blooms, and some open-hearth steel 

 rails were rolled. Estimating the amount of 

 such rails to be near 100,000 gross tons, the 

 total American steel-rail production in 1882 

 would be 1,300,000 gross tons, against a total 

 in 1881 of 1,210,285 gross tons. The fourteen 

 steel-works whose reports are thus compiled 

 contain 35 converters. Relative to the pro- 

 duction of steel throughout the world, it ap- 

 pears from the latest published statistics that 

 there are now in England 23 steel-works, with 

 about 115 converters, of a productive capaci- 

 ty of 1,461,000 tons per annum; in Austria, 

 14 steel-works, with 36 converters, and a ca- 

 pacity of 350,000 tons ; in Belgium, 4 steel- 

 works, with 18 converters, and a capacity of 

 380,000 tons; in France, 7 works, with 34 

 converters, and a capacity of 632,000 tons; 

 in Germany, 23 Bessemer and Thomas steel- 

 works, with 80 converters, and a capacity of 

 about 1,300,000 tons; in Russia, 5 steel-works, 

 with 10 converters, and a capacity of 100,000 

 tons; and in Sweden, 35 converters, with a 

 capacity of 80,000 tons. The total number of 

 converters in the world is, therefore, about 

 360, with an aggregate annual productive ca- 

 pacity, in round numbers, of 5,800,000 tons of 

 steel. 



PRODUCTION OF ALUMINUM. An improved 

 process for producing aluminum, whereby the 

 cost of the metal is reduced by about 80 per 

 cent, and the time required to prepare it from 

 nine months to a few days, has been invented 

 by Mr. James Webster, of Hollywood, near 

 Birmingham, England. Alumina, from which 

 the metal is obtained by precipitation, is pre- 

 pared by burning alum and pitch, as follows : 

 A given quantity of alum and pitch, which are 

 first finely ground, is mixed together and placed 

 in a calcining furnace, when 38 per cent of 

 water is driven out, and the sulphur, potash, 

 and alumina are left, with oxide of iron. The 

 calcined mixture is then put into vertical re- 

 torts, and steam and air are forced through, 

 after which a residue of potash and alumina 



only is left. This residue is afterward placed 

 in a vat filled with warm water, which is heated 

 with steam. The potash is thus leached out 

 and the alumina left as a deposit. The potash - 

 liquor is then run off and boiled down, while 

 the alumina precipitate is collected in sacks and 

 dried. It is then ready for making chloride of 

 aluminum. The alumina deposit thus obtained 

 contains about 84 per cent of pure alumina, 

 while that which is obtained by the old pro- 

 cess of precipitation has only 65 per cent. For 

 conversion to aluminum, the chloride is treated 

 with sodium. This process, if its success is 

 verified, is probably destined to make it pos- 

 sible to employ aluminum, as an alloy, econom- 

 ically in many manufactures for which it is 

 preferable to any metal now known. It is 

 eight times more conductible to the galvanic 

 current than iron, and by this, and the fact 

 that it does not rust, it is valuable for tele- 

 graphic purposes. Its tensility, and lightness, 

 and un susceptibility to corrosion indicate a 

 great adaptation to the purposes of ship-fittings, 

 particularly for steamship propellers. The al- 

 loy, it is said, will bear a strain of forty-two 

 tons to the square inch, or twelve tons more 

 than Bessemer steel. A more particular state- 

 ment of its mechanical powers was given by 

 Mr. W. H. Barlow, F. R. S., at the last meet- 

 ing of the British Association, in the relation 

 of some experiments he had made on the sub- 

 ject. He found the ultimate tensile strength 

 of the metal to be about twelve tons to the 

 square inch. The range of its elasticity was 

 indicated by an extension at the yielding-point 

 of one two-hundredth the length of the piece, 

 or about three times that of steel, and five 

 times that of wrought-iron. The mechanical 

 value of the substance, as indicated by its 

 strength in relation to its weight, is about 

 equal to that of steel of thirty-five tons per 

 inch. These properties point to a great suita- 

 bility of aluminum for cases where strength 

 combined with lightness and a great range of 

 elasticity are required. Mr. Webster has also 

 discovered that aluminum may be deposited on 

 several other metals, and may be soldered and 

 welded. 



ZINO. The present methods for the reduc- 

 tion of zinc ores by distillation are expensive 

 and cumbrous. In the search for more econom- 

 ical ways of preparing metallic zinc, attention 

 has been directed to the feasibility of produc- 

 ing it by a wet process and electricity. Three 

 methods have been proposed which depend 

 upon the employment, severally, of hydro- 

 chloric, nitric, and sulphuric acids. In the 

 hydrochloric-acid process the acid is placed 

 in contact with the ore in order to produce 

 a hydric chloride, neutral and concentrated; 

 after which the liquid is treated with an electric 

 current, by which the zinc is precipitated in a 

 pure metallic state. The iron, which would 

 otherwise be precipitated with the zinc, is pre- 

 viously eliminated by means of some oxidizing 

 body. The chlorine, which is liberated when 



