184  CONTRIBUTIONS    TO    ECONOMIC    GEOLOGY,  1906,  PART    I. 
Regarding  the  other  conditions  of  marketing  the  products,  the 
same  facts  prevail  in  the  gray-ore  district  as  in  the  other  iron  regions 
of  Alabama.  It  therefore  may  be  instructive  to  compare  this  dis- 
trict with  the  well-known  and  successful  Birmingham  district,  noting 
wherein  the  costs  in  one  exceed  the  costs  in  the  other.  The  cost  of 
mining  gray  ore  will  necessarily  be  the  higher  on  account  of  its  mas- 
sive quartzitic  character,  the  interl animation  of  the  ore  and  slate, 
and  slope  rather  than  open-pit  mining.  The  cost  of  smelting  will  be 
considerably  lower  in  the  Birmingham  district,  owing  to  the  lesser 
cost  of  coal  haulage.  The  costs  of  marketing  the  product  from  both 
fields  will  be  practically  the  same.  It  seems  evident  that,  in  order  to 
offset  the  greater  cost  in  mining  and  smelting,  the  gray  ore  must  run 
at  least  f)  points  higher  in  metallic   iron    than  the  Birmingham  ores.  I 
