880 GEOLOGY OF OHIO. 



Analyses of Mill Cindkks from Marietta Rolling Mill. 



Analyses of Mill Cinders from Columbus Rolling Mill. 



Silicic acid 



Iron oxide 



Alumina 



Mangannse 



Lime pliosphato 

 ** Citrbtmate 



MagiK'Kia 



SulpliMr 



Totals.... 



JI I illic iron ... 

 } '!ic»,sp!joiHo 



The foregoing analyses, inst,3ad of confirming the common traditional 

 belief that cinders from the heating farnaces are worthless, show that, 

 as compared with the cinders from the puddling furnaces, they are the 

 purer and better of the two. The average phosphorus in the former is 

 33 per cent; while that in the latter is 1.07 per cent., or more than 

 three times larger. There is also a trifle less sulphur in the heating 

 cinder. There is in it a little more iron, and a little more silica. Iq re- 

 gard to the latter element, it had generally been thought that inasmuch 

 as the heating furnace has a sand bottom, the sand would be blended 

 with the ciader and render it valueless. The analyses do not sustain 

 such a conclusion. The average of the three analyses show only 0.98 

 per cent, more silica in the cinder formed in the heating farnac?. In 

 one case the silica is even lefs than in tlie other. There existed an im- 



