COJSTKIBUTIONS    TO    ECONOMIC    GEOLOGY,   1903.  [bull.  225. 
is  very  expensive.  If  a  sufficient  supply  of  the  brilliant,  light,  bitu- 
minous coal  could  be  developed,  it  would  probably  be  directly  avail- 
able for  fuel.  All  these  coals  contain  a  large  percentage  of  volatile 
matter,  and  the  gas  which  they  contain  might  be  separated  and  profit- 
ably used  for  fuel. 
The  incoming  of  large  mining  enterprises  into  the  region  should 
give  impetus  to  a  careful  and  well-considered  study  of  the  utilization 
of  this  important  natural  source  of  energy. 
