426 



METALS. 



largo pieces should not be mingled with small, 

 and those muffles containing the larger pieces 

 should be placed in the furnace first. On the 

 other hand, the smaller objects are placed on 

 the sole of the furnace. Without these pre- 

 cautions, many pieces may be burned, or badly 

 decarburized the latter becoming something 

 intermediate between iron and steel. When 

 the operation is deemed complete, the fire is 

 allowed to fall, but the furnace is not un- 

 charged until it has gradually cooled. Prac- 

 tice plays an important part in the manage- 

 ment of the firing, as the temperature can be 

 judged of only after prolonged experience." 



Special Method of Blooming. The American 

 Exchange and Review gives the following de- 

 scription of a modification of the Catalan pro- 

 cess in the old form of the forge-hearth at the 

 Logan Iron-works, Bellefonte. The writer re- 

 gards the plan as extremely simple and direct, 

 and resulting in the production of a very supe- 

 rior iron : 



The furnace is a few inch.es above tlie general floor 

 of the forge-house, and the size about large enough to 

 make one bloom of 200 or 225 Ibs. It is about three 

 by four feet, the long way running back from the 

 workman. The instrument for turning, lifting, and 

 aggregating the iron is called a " furgeon," and an- 

 swers to the rabble of the ordinary puddling-furnace. 

 The waste-heap passes up and through a chamber 

 immediately over the forge-hearth, where the pigs 

 are placed, which become red-hot before they are 

 ready to be drawn down upon the bed of charcoal 

 previously prepared. The pigs thus drawn down 

 upon the charcoal bed are covered, and the blast 

 turned on into both tuyeres right and left. After a 

 few minutes the iron begins to melt ; it is decarbon- 

 ized by the blast, is worked into shape by the fur- 

 geon, and then lifted up clear of the bed and laid 

 upon the top of the same bed again, some additional 

 charcoal put around, and the blast turned on. The 

 iron now is melted in what is called the sinking pro- 

 cess, wherein the iron drops through the coal into 

 the hearth until entirely passed into the hearth ; there 

 it is again agglomerated into the ball, or " loup," by 

 the furgeon (pronounced furgun}, the blast having 

 previously been turned on fully ; it is then lifted out 

 a balled loup and carried to the hammer. The cinder 

 is tapped off through a hole in the front iron plate, 

 and is rich in iron, with so much silex that it easily 

 emits sparks when the penknife-blade is struck 

 against it. Of course, this process is attended by a 

 large^loss of iron, while the loup, which gives rise to 

 the cinder, is not thereby improved, as in the pud- 

 dling-furnace. But in this particular instance the 

 iron is singularly pure, and the blooms command 

 $85 per ton at the forge. One ton and a half of pio- 

 yields 2,464 Ibs. of bloom. The charcoal-furnace 

 yielding the iron is nearly adjoining the bloomery. 



This furnace is only 32 ft. high, about 26 in. across 

 the tunnel-head opening, 8k ft. bosh, and the sla<* is 

 allowed to flow out from the hearth whenever it 

 rises above the fore-hearth. The breast is covered 

 Avith a simple plate of iron ; the cinder is always in 

 sight ; as soon as the iron appears, the crucible, or 

 tapping-hole, is opened, and the iron is tapped off 

 into iron moulds. There are three casts per twenty- 

 tour hours, two tons per cast ; 150 bush, hard coal 

 (18 Ibs. to the bushel) to the ton made. Charges, 

 <00 to 750 pipes ore (brown hematite), 27 bush, char- 

 coal. 80 Ibs. gray limestone of good quality: pressure, 

 a half to three-quarters of a pound per inch ; nozzle 

 two and a half ; two wooden blowing cylinders worked 

 by water-wheel. Some finery cinders, about 30 to 

 40 Ibs., are added to the charges, and said to improve 



the iron, which at present (May 26, 1869) is all forge- 

 iron, and used at Stewart & Co.'s wire-factory, and 

 reported as a very fine iron. 



/Smelting, carlurizing, and purifying Iron. 

 Some processes for facilitating this work 

 have lately been patented by Mr. Isham Baggs, 

 of London. In charging the furnace he dis- 

 penses with coal or coke, using instead coal- 

 gas, hydrogen, carbonic oxide, or other com- 

 bustible gas, or the vapor of any hydrocarbon 

 under pressure, and in combination with a hot 

 or cold air blast. In the case of the inflam- 

 mable hydrocarbon vapors, the same may be 

 forced into the furnace under the pressure of 

 their own atmospheres, or by means of me- 

 chanical appliances. The gases and vapors 

 which are employed for the purposes of this 

 invention may be previously mixed with the 

 air furnished by the blast, or may be caused to 

 meet the air in the furnace or at the tuyeres. 

 The proportions of the mixture, when a com- 

 bination of gas or vapor and air is employed, 

 are subject to constant regulation by" valves. 

 One very convenient mode of obtaining com- 

 bustible gases for the purposes of this inven- 

 tion is to generate coal-gas in the usual way, 

 and then carbonic oxide, and to blow air or 

 carbonic-oxide gas under pressure through the 

 retort containing the residual coke. 



For the purpose of carburizing the iron, 

 whether in or out of the furnace, as may be 

 desirable, coal-gas or other carbides, or other 

 materials containing carbon, are blown through 

 the furnace, or brought into contact with the 

 molten metal by blowing them through it. 

 Carbon in any suitable form or combination 

 may also be directly introduced into the fur- 

 nace for the purpose of carburization ; and, 

 although generally for smelting purposes it is 

 desirable to exclude all solid mineral fuel from 

 the furnace as part of the charge, yet, where a 

 suspension of operations is necessary, such a 

 charge of coal, coke, or other fuel, may be in- 

 troduced into the furnace as will prevent the 

 materials, on renewal of work, from falling 

 through the crucible or any iron remaining 

 therein or below it, from being permanently 

 solidified. When purification is required, hy- 

 drofluoric acid is blown through the molten 

 metal on its way from the furnaces, the gases 

 being mixed with common air, or with some 

 gaseous diluent. Mechanics' Magazine. 



Iron Analysis. Gintel gives an easy method 

 of determining the impurities in cast iron. 

 The iron is reduced to as minute a state of 

 division as possible, and is then treated with a 

 strong solution of perchloride of iron, as.jiearly 

 neutral as possible. The mixture is kept 

 heated for ten or twelve hours, at the end of 

 which time almost all the iron will be found 

 to have dissolved, leaving, as a residue, the 

 carbon, sulphur, phosphorus, and silica, to- 

 gether with the little iron left undissolved. 

 This residue has only to be well washed, oxi- 

 dized and dissolved, and the sulphur estimated 

 as sulphate of baryta. The exact plan directed 



