191Ji\ Certain Mineral Resources 25 



tlie viilue of the ore increases with each unit over this. Ores aa 

 low as 45 per cent Qv^O^ find a ready market if they are low 

 in silica. The Korth Carolina ores are high grade and usually 

 low in silica. 

 Chapei, Hhi,, N, C. 



{Continued in next issue) 



