COLLKCTIONR IN KCONOMIC GEOLOCY AND MK rALI.TlCi; V. 1 17 



i(»iiii(ls, ('(Hisistiii^or oiii' It.inosv dl (M(!li of I lie (lin'fi'ciil iMcs. and llif 

 i('(|iiisit»' im(iiht'r()rc(tlv»';iii<l limcstuiic. Tlic cliar;;*' Irscciids imirormly 

 iiillic t'liinacc, and lr<»in IS t«t L'O lionrs claiisr hctwrcii (•liar;,Mii,u t In' 

 ore at tlui lop and lapping' \\\v niclal iVoni lln- sann* ore at llic holtoin. 

 Tlir Inniacos arc tapped six times in L'l liouis, alumt .'.Otons of iron 

 antl ivi tons of slaj; hein^ taken at each taj). While the metal is 

 being tapped a sample is taken ont and east in a ehill mold, in order to 

 ^aiide the steel blower in the eonversiou. Theie are nin(^ grades of 

 iron reeogni/.ed, \vhi*',h are the ordinary grades ol" one to three divi led 

 l)y fourths. The iron generally contains about lA per cent, ofsilicon, 

 and .i.] i)er cent, of earbon. 



The pig-iron from the blast fiii-nace is tapped into ladles holding about 

 !(• tons of metal, and carried direct to the converter, it takes from 

 one-half to three (piarters of an hour to transi)ort the metal. One 

 charge was successfully blown after standing 14 hours. During the 

 time the pig iron is stancbng in the ladle there i.s a constant separa- 

 tion of graphite from the metal going on, and samples taken just bo- 

 tore pouring into the converter always show a marked tendency towards 

 white iron. A little over 1 i>er cent, of the iron remains in the ladle 

 in the form of a skull, which is periodically removed. 



The converter is constructed with a removable shell, and is hung on 

 (•ast-iron trunnions. The Viody is cylindrical, 10 feet in diameter and 

 llA feet long, and the bottoms, of which 1.") are sup[)lied for each 

 converter, are .somewhat hollowed out. There are IS tuyeres, each 

 having twelve three-fourths inch holes. The converters are arranged 

 in a row, and discharge their steel into ladles upon receiving cranes, 

 which deliver the ladles to the casting crane from which the ingots are 

 cast. The ingot molds are arranged in pairs, and four \ni\rs are gen- 

 erally used for each blow. Tlie height to which the molds are tilled 

 is governed by the weight of the rail to be made. 



At the beginning and end of the cast a sample of the steel is cast in 

 a small ing(>t, and subje(!ted to tests to determine its quality. For this 

 purpose they are drawn out to a l)ar 1 inch s(piare, under a steam 

 hammer. One end of this bar is drawn to a rod one-<piarter inch sijuare. 

 The 1 inch bar is nicked while hot, and broken when cold w show 

 the fracture, and the (piarter-inch rod is bent cold on the anvil. A 

 sharp beiul at right angles without showing any tendency to fra(!ture is 

 considered satisfactory, but in many cases they are doubliMl flat with- 

 out breaking. 



As soon as the ingots are cohl cnongh tlic molds are lit ted olf tVon\ 

 them and tlic\ arc taken to the rail mill, w hcr<' they are rolh-d into lails 

 in a single heat, eai.'h ingot making lour lails. The steel made is of 

 exi'cllent <pialit.\ as shown by the mechanical tests, and its composition 

 is kept very nnitiii Hi. ctMitaining alxml o.o. ". I per cent, silicon, (M IJ to 

 O.llS pd <'cnt. pliosplini ns, l.L'Oto 1. LI I per ecu I . inangane.NC. (i..!ri lo (I. I 

 jjor cent, ot <arbon, and (i.(»J."> per cent, sulphur. 



