COLLECTIONS IN ECONOMIC OKOLOGY AND METALLI;U(;Y. IGl 

 The blast furnace slag coiitaiiis : 



l*or cent. 



Silicii (SiOj) II.'.m; 



Altiiiiiuu (AI-O3) 7. (ij 



Lime(('ii()) 'JT.. 04 



Mrt;,'iieai!i (MjrO) 17.75 



rroiitxitlo of iiuinj;am'.so (MiiO) »;. r>7 



Protoxide of iron (KcO) 0.2'.i 



Alkalies not »U'tenuiiio«l 



'M. .'>7 



As no si)iegeleiscn or ordinary cast-iron is employed to recarburize 

 the metal, the "blow" must be stopped when the proportion of carbon 

 in the steel is reduced to tlie i»roper degree. Notwithstanding this, 

 the steel is entirely free from re<l shortness. 



The following analyses show the chemical compositions of the various 

 classes of steel employed for the [)urposes specified : 



(a) Steel for soft plates, railway axles, etc. 



(6) Steel for ;;uii liarri Is, shafts, etc 



((•) Soft steel for tools, saws, etc 



('/) Hard steel for tools, chisels, taming tools, etc 



Carbon. > Silicon. 



Manga- 

 oeae. 



P«r cent. Per cent. \ Per cent. 

 0. 085 0. 008 Trace. 



0. 25 0. 036 0. 234 



0. 70 I 032 0. 250 



1.05 I 0.067 0.355 



Phosphor. Sulphur. 



Per cent. ' 



0.025 Trace. 

 0.022 Do. 

 0. 023 Do. 



0. 028 Do. 



I 



An analysis of the slag from the converter, taken at the close of the 

 process, shows its composition to be as follows : 



Per cent. 



Sinca(SiOi) 46.70 



Alumina (AliOs) 4.24 



Lime (CaO) 0.48 



Magnesia (MgO) r. 0. 17 



Protoxide of manganese (MnO) :Vi. 37 



Protoxide of iron (FeO) 15.63 



99.59 



KIKKAI.liY S KXrKUIMKNT.M, IVijUIUY INTO TUK MKCIIANIC.vr, I'Rol'KUTIKS OF FA- 

 CE KSTA .STKKL. 



Mr. David Kirkaldy, of London, has made a very elaborate and sys- 

 tematic investigation of the product of the Fagersta works. The exam- 

 ination was designed to show the actual mechanical properties of the 

 average product, and this wns carried out very carefully. 



A selection of the specimens tested has been placed on exhibition in 

 tile Museum. 



Srriis A. 



To ascertain tiic mechanical properties of twehe h;iiniiiered bars of 

 v.moiis degrees of hardness, or the behiivior of the steel when sub- 

 jeeted to the various stresses which occur in eiigjiieerin.L; works, namely, 

 DUO— No. 4L' 11 



