METALLURGY. 



529 



fine piece of steel by any other process are the 

 oxidation of the surface of the metal by con- 

 tact when heated with the air, and the buck- 

 ling and twisting of the ribbon in the oil-bath. 

 Both of these troubles are avoided in Mr. Sedg- 

 wick's ]>n> 



Apparatus. The advantages of magnesite as 

 a refractory material in furnace-linings are thus 

 summarized by Herr K. Sorge: The charge 

 may be dephosphorized without difficulty to 

 the extent of 98 per cent, of its total phos- 

 phorus; magnesite bottoms allow of the addi- 

 tion to the charge of 30 per cent, and upward 

 of iron-ore, and thereby facilitate the use of 

 every kind of said material ; magnesite bricks 

 may be made of very regular shape, so that 

 the building of the hearth in an accurate and 

 durable form is much facilitated ; magnesite 

 may be built up in direct contact with silica 

 brick-work, which is not possible with any other 

 basic material : the durability of a magnesia 

 lining far exceeds that of any other basic sub- 

 stance, and it is therefore less costly for re- 

 pairs: magnesite, when exposed to the action 

 of the basic slags and metallic oxides, resi-t~ 

 corrosion better than any other known sub- 

 stance ; the absolute indifference of bricks and 

 burned magnesite to the action of the air makes 

 it possible to preserve them in quantity for 

 any time without fear of alteration. The dan- 

 ger of using a partially altered material, and 

 therefore one of small durability, as may hap- 

 pen with dolomite, is completely avoided with 

 magnesite. 



The difficulty of supporting the ore and fuel 

 in the furnace, as is done in ordinary furnaces 

 by the coke, which was the chief obstacle to 

 the making of pig-iron by natural gas, is met 

 in Mr. J. T. Wainwright's furnace by a series 

 of pipes protected with fire-clay tiles. The 

 pipes are kept cool by turning a portion of the 

 blast into the space between them and the 

 tiles. The furnace is fitted with a combination 

 chamber, into which the gas and air furnished 

 from an ordinary cupola are admitted through 

 separate pipes. Ordinary cupolas may be easi- 

 ly altered to use the new fuel. 



A naphtha refuse-burning furnace, acting 

 both as a calciner and a smelting-furnace, has 

 been introduced at the Radabeksky Copper 

 Smelting Works of Messrs. Siemens Brothers. 

 In a thirty-days' run it smelted 2,076,911 

 pounds of 7-per-cent. ore, consuming 408,- 

 835 pounds of naphtha refuse, at 42*. per ton, 

 and yielded 810,737 pounds of regulus, con- 

 taining 25 per cent, of copper; or to pro- 

 duce 2,000 pounds of regulus required 1,008 

 pounds of refuse, costing 21*. 3d. This is said 

 to work 3-5 times faster than the ordinary ore- 

 furnace, and to be cheaper at these works than 

 when wood is used. 



An important improvement in puddling, in- 

 troduced by the Xorth Chicago Rolling Mill 

 Company, includes taking the molten iron di- 

 rectly from the blast-furnace to the puddling- 

 furnace. The results are very satisfactory, 

 VOL. xxvin. 34 A 



both as to the quality of the puddled bar and 

 in a considerable saving that is effected in fuel, 

 time, and other items. 



The composition of the Dinas fire-bricks and 

 cement, which have gained an excellent repu- 

 tation, is shown by the analysis of Mr. James 

 S. Merry to be silica, 98-1(1 : alumina, T04; 

 oxide of iron, 0'56 ; lime, 0.53 ; magnesia, a 

 trace; and water, 0*1. 



The Lash open-hearth furnace, which i pe- 

 culiarly adapted to the use of gas, is largely 

 employed at Pittsburg, where twelve tun. 

 varying in capacity from 40 to 15 tons, are 

 actually at work and four others are building. 



By the use of the new foundry ladle of 

 Goodwin & How, Westminster, the ordinary 

 method of skimming molten metal by hand is 

 dispensed with, scoria and ashes are prevented 

 from entering the mold, the densest and clean- 

 est metal can be poured from the bottom, and 

 the metal can be kept hot in the body of the 

 ladle by the usual covering of sand while pour- 

 ing. 



3Ii-*ellaneons. The Director of the United 

 States Mint, in his report on the production of 

 the precious metals in the United States dur- 

 ing 1887, states that the production of geld 

 amounted to 1,596,500 fine ounces, of the value 

 of $33,000,000. The production of silver 

 amounted to 41,269,240 fine ounces, of com- 

 mercial value about $40,450,000, and of the 

 coining value of 53,357,000. The gold pro- 

 duction fell off from that of the preceding 

 year, when it was $35,000,000. The produc- 

 tion of silver increased over that of the pre- 

 ceding year, when at coining value it wa< $51.- 

 000,000. The production was contributed by 

 States and Territories as follows, in coining 

 values : 



The property which the electric current pos- 

 sesses, said Mr. W. H. Preece, in the British 

 iation, of doing work upon the chemical 

 constitution of bodies so as to break up certain 

 liquid compounds into their constituent parts, 

 and marshal these disunited molecules in regu- 

 lar order, according to a definite law upon 

 the surfaces of metals in contact with the 

 liquid where the current enters and exists, has 



