METALS. 



HI 



nu.ul.ls vary in capacity from 100 llm. to 

 as. Tlu- furnatvs HIT iirrangi-d ulon- the 

 tlu- \\hule leii-th of tho building, HI id nro 

 acccssil.lo by means of galleries undcrm-atli. 

 iidiu-tiniT the, incited motnl to 

 the in- . ul. U are strontrly constructed of wrought 

 i.iu-.l on tin' inside with lire-clay and 

 II mouthed at the end next the 

 mould! Tin- signal being given, the furnaces 

 aid the work begins. One man 

 with :i pair of pincers seizes a crucible, and 

 - it to two of his fellows, who carry it at 

 to a part of the shop floor left free for 

 ; mrpose. Near at hand are a regular line 

 of assistants standing two by two, awaiting the 

 advent of the crucibles. Upon the arrival of a 

 crucible, two of the men seize it by a double 

 pincer, empty it into the channel assigned to 

 . and then cast the empty crucible down a 

 funnel into the cellars below the shop, and re- 

 sume their position in line. This establishes a 

 c continuity of operations, and prevents 

 the possibility of confusion and over-crowding. 

 In a few minutes, the vast cavity, containing as 

 :i maximum 86 tons of metal, is filled. As a 

 rule, for the purposes of avoiding night work, 

 the meltings are so managed that the running 

 takes place early in the morning or during 

 some after portion of the day; and the only 

 men left in the work at night are those having 

 charge of the maintenance of the furnaces, as 

 the removal of the ingots is also effected in the 

 daytime. In about two hours after casting, 

 the ingot, except when of excessive dimensions, 

 is sufficiently solid to be lifted by the movable 

 crano and taken away ; when the large ingots 

 are not required at once to be put under the 

 hammer, they are covered with ashes and half- 

 consumed debris, and a wall of dry fire-bricks 

 is built around them to keep in the heat. The 

 slow combustion of this otherwise valueless 

 fuel, prevents the ingot from becoming quite 

 cold. One of the chief peculiarities in Mr. 

 Krupp's system, is that all new inventions and 

 -ses are thoroughly tested before adoption 

 in his establishment. It has an experimental 

 shop replete with crucibles, furnaces, retorts, 

 and scientific apparatus of every kind, by 

 which proposed improvements in the manu- 

 facture of cast-steel are submitted to careful 

 trial, and if demonstrated to bo really valua- 

 ble are introduced in his works. (Mech. Mag.) 

 The Bessemer Process. At a recent meeting 

 of the British Association, Mr. Bessemer ex- 

 plained some improvements in the practical ap- 

 plication of his process for the conversion of 

 melted cast-iron into steel, by moans of which 

 he had slowly advanced from operations of 

 40 Ibs. to 25 tons at a time. Ho hoped that 

 the cost of manufacture would eventually bo so 

 much reduced as to make the steel available for 

 general purposes. At a cost of 2 a ton, old steel 

 rails could be converted into round steel bars, 

 with a waste of only H to 2 per cent., worth 18 

 per ton. Ho believed, that after manufacturers 

 had bon remunerated for their expensive ma- 

 VOL. TI. 81 A 



chiiu-ry. M.. 1 might bo produced at a little 

 more cost than the best iron. Tens of thousand! 

 of tons of steel are now sold at 18 a ton, 

 whereas the former price was from 36 to 80 

 acci.nlini: to quality. 



The Conversion of Cast-iron into Steel. M. 

 (lal Cazalat presented to the French Academy 

 in January 1806, a note describing "anew pro- 

 cess for quickly and economically converting 

 any mass of cast-iron into steel." He passes 

 superheated steam into the fused iron. This is 

 decomposed in traversing the mass ; the oxygen 

 burns the carbon and oxide of iron, while the 

 hydrogen combines with and removes the sul- 

 phur, phosphorus, and other metalloids, the 

 presence of which would render the steel 

 brittle. When the color of flame at the top of 

 tho mass indicates the proper degree of decar- 

 bouization, the steel is run out. The author 

 operates either in a cupola, or in a reverbera- 

 tory furnace of his own construction, in which 

 the waste heat from the furnace is used to 

 produce steam. Common steel, ho says, can 

 always bo regularly produced by completely 

 decarbonizing tho cast-iron, and then adding 10 

 per cent, of spathic cast-iron, which restores to 

 the iron the amount of carbon necessary to 

 effect the conversion into steel. By a peculiar 

 contrivance, he shuts off tho current of super- 

 heated steam from the metal, and passes it into 

 tho chimney, where it serves to increase the 

 draught in the furnace, and thus leaves the 

 steel in a state of tranquil fusion for about 15 

 minutes, and so gets a perfectly homogeneous 

 mass. He removes bubbles in his castings by 

 covering the mould hermetically with a sort of 

 hat, from the top of which rises a pipe in which 

 are placed 6 or 10 grammes of a mixture of 80 

 parts of saltpetre and 20 parts of charcoal. By 

 opening a stopcock, the powder is allowed to 

 fall on the metal, when it ignites and produces 

 a large quantity of gas, which exerts pressure 

 on all parts of the casting, removing the bub- 

 bles and increasing the tenacity of the metal. 



A new Theory of Iron and Steel. M. de 

 Cirancourt, in a paper read before the Frenchj 

 Academy, puts forth a new theory of iron and 

 steel. Oxides of iron have usually been con- 

 sidered as degrees of oxidation of tho same 

 metal ; but the author adopts tho view first 

 suggested by Berzelius, that there are two 

 varieties of "iron metal," to which he gave 

 the names of ferricum and ferrosum, supposed 

 to represent two allotropio states of iron. Fer- 

 rosum is the metal extracted from the peroxide 

 of iron, through tho reducing agency of hydro- 

 gen ; the nearest approach to this is the com- 

 mercial iron known as bright iron. The iron 

 derived from the anhydrous peroxide is the 

 metal called ferricum. The common sorts of 

 foundry iron aro this metal with some carbon. 

 The author says, that certain kinds of cast-iron 

 identical in their chemical composition appear 

 so different from each other, and give such 

 opposite resnlts in working, as to compel us to 

 distinguish them in practice. The real charac- 



