508 



MKTALLl 



cording to the form present, will. the author- think. 

 account for many of th< m< on-i-;< 



in tht* stat-ment-'u-ually made by inetallurgi-t- in 

 regard to tin- 1 tin- el. ment. 



The power of aluminum t<> n-.lu. -arb..nic 

 at high t- - has been used by IV.. f. .1. <*. 



1 an.l !'. R. Knowlw to measure') i 

 bility ( furnace gases of clay steel-melting cruci- 

 bles. In .i'jcct. 

 .<hor- sy that in posting puro carbonic 



iliiminum th-- metnl became coated 

 with a mixture of jilumina ai. 



through II: 



mil.l Heel containing about 4 per ..m.i- 



num. the percentage of carbon was raised. Ti 

 perimriit* m m-a>uring p-rmeabii irricd 



nut by nit-limi: Swedish j r ,,u containing 



99-go 'h calculated quantities of aliimi- 



nuin. H "I 1 'H'l re-melted. 



wa> found that in . h greater |>arl 

 >f the aluminum had been oxidized and the 



I*. .11 liberated 1 .r..n into hard 



steel The most important practical feature of the 



ment wji- -hiiwn that tin- wall- 



crucible form little protection against the absorp- 



f sulphur by tin- im tal m-Mc it. 



nited for the use of car- 

 borundum, or carbide of silicon, in the manufacture 

 of steel. The liner grades of this sub-tan< 

 HI : M ibrash es. whill 'he POOIIM qualities an- n't 

 valuable for this purpose, and may be sold cheaply. 

 de of silicon in molten steel splits up and gives 

 both carbon and silicon to the metal. 



ile adopted by M. A. A. Cunningham from 

 - that have been made on the sub- 

 lint: the approximate trnsile strength of 

 Otool is, to a base of 40,000 |>ounds per square inch. 

 to add 1,000 pound- f..r every OOi j>er cent of car- 

 bon, and 1,000 pounds for every CK)1 |HT cent, of 

 phosphorus, neglecting all other elements in nor- 

 mal steels. Radical - between calculated 

 and actual strength indicate mixed steels, segrega- 

 incorrect analyses, or unusual treat m.-nt in 

 manufacture. The author has 1 -n tauu'lit by years 

 of experience that carbon is the most desirable ele- 

 ment forgiving >trenrth to steel, that definite re- 

 sults can be produced by varying its amount, and 

 that the gain of strength due to its increase is ac- 

 companied with less loss of desirable properties 

 than is the case with any other hardeners. All 

 elements occurring in carU.n steels may be 

 considered impurities or antitfotes. 



In a method which he has patented for casting 

 armor plates, and at the Maie time hardening the 

 face, Mr. William Beardmon- forms a mold I 

 metal with the usual lining, into which the molt* -n 

 metal is run through a pipe terminating at the bot- 

 tom of the mold till the level has been reached that 

 will insure the n-.juir.-d thickness of casting of t ho 

 tempered face. Meanwhile an immense number of 

 jets of cold air are playing on the thin Lot torn. 

 whereby temjer i jfiven to tne metal as it sets from 

 the bottom up. When the first thickness of metal 

 ha* become sufficiently cool, softer metal to form 

 the back is poured through another jet did,ari:ini: 

 at several level*, so that any desired thickness of 

 the black metal can be insured. The composite 

 plate thus made has to be machined in th. 

 way. and is ubj-ti also to the customary face 

 hardening by chilling. 



In an American apparatus worked by electrical 



Ewer for char:: MS furnaces, described by 



r. Jeremiah Head at the spring m.tm-of the 

 Iron and Steel Institute, a powerful frame r iraun- 

 tree is run up in front of the furnace, from whj'-h a 

 massive arm is projected by means of an el- 

 motor. This arm is provided with a grapple which 



grasp ! means the boxes cont 



thefurna> -. The furnace door is 01 



and the arm carries the iron box. with it- <! 

 of pig iroi. into the furnace; b\ an<>tl 



ii i> rotated and di-po-its 



materials into the lire, when the box i- withdnn 

 by the arm. The 0| eintinucd till 



whole eharge is in |M>-UIOU on tin- hearth, when 

 appnratn- -n to I he m-xt funin 



The -,.mbined open-hearth process of 

 an. I Thn-1 embrace- t wo open-heart h furnaces. 



divided into two Mages, the 

 run when half treated througl: 

 the primary to a secondary furna -e \\ hi -h lias the 

 nature of a" finery. The perfect elimination of the 

 pho-phoru- i- not intended in the upper furnace, 

 wlienee le-s limemav be added than would other- 



uid the (|uantily of -l.-i- to 

 melted i- materially diminished. The plan of 

 ing adopted <on-i-t- in charging nearly all 

 -iliceous and phosphori<- pii: into the primary 

 iy all the scrap into the fmi'sl 

 furnace, adding in cadi su< h ipiaul ities of 

 lime. etc.. as are demanded. Tin- advantages 

 claimed for tin- apparatus of an increa 

 and a material reduction in the consumption 

 lime and basic material for lining the fui 

 hearths. 



The object of Mr. II. \V. llolli- in d igning hial 

 :;ile reheating furii. to ilispense with 



regenerat iiiLT chamber-, to obtain conlinnou- work- 

 ing without rever-ing the course of the llai 

 get rid of t he disadvantages attendant upon frequent 

 stoppages for clearing or renewal (.f brick cheekcr- 

 work. and to introduce the flame in such a \ 

 to obtain equal heating over the whole floor of t he 

 furnace chamber. This i- accomplished by intro- 

 ducing a gas flame through a stratum of' highly 



1 air in the roof of the furnace, the 

 pouring down upon the slabs or piles to be I 

 and parsing along the floor of the working chamber 

 to an out let port at each end. 



A new process suggested for prevent in:: m-t in 

 iron structure- COHH-IS in treating the iron \\ith a 

 solution of ferro-cyanide. This forms a coating of 

 cyanide of iron that is described a- beinL' uniform 

 and impermeable, and of such a naturea- 

 to protect the iron covered by it. The -<-hr 

 mixed with a flax seed varnish, to which a little 

 turpentine or benzol has been added, -o as to form 

 a homogeneous emulsion which can be applied 

 without difficulty. The <>va|H>rat ion of the alcohol 

 leaves the flaxsecd varnish, which forms a coat and 

 protects the cyanide of iron deposited upon th.- 

 metal. The iron requires no preparation f"i 

 treatment except cleaning from ru-t a! 

 formed. 



In the I'ehling casting process all heavy hand 

 lalnir i- supplanted by machinery, the -and in th- 

 pig iron is eliminated, and th' 

 hitherto a considerable adjunct tothebla-t fur 

 i- dispensed with. 



rrecjoiix Metal-. The treatment of the j-. 

 gold ores at (iibbonsville. Mont.. .: 

 to A detailed description bv C. ('. Hurgcr. of amal- 

 gamation in the battery and saving of concent 

 roasting' in twenty-four hours from ] to 15 t' 

 concentrates with from :',:{ to 40 percent, -ulphur in 

 a two-hearth I'earce turret furnace, supplement* 

 a small hand reverberator) furnace holding tv 

 ton chart:*-- to insure dead' roa-tin^ without dimin- 

 ishintr the capacity of the mechanical fur 

 chlorination in a 1 j -ton T hies barrel ; filtering 



ressed air in steel-lined cylinders 

 trunnions; settling any -lime- that pass the 

 cloth; and precipitating with ferron- -uli 

 The cost of chlorination is less than fr> per 



