376 
CONTRIBUTIONS    TO   ECONOMIC    GEOLOGY,  1905. 
While  it  is  probable  that  by  careful  grinding  this  material  could  be  utilized  for  c 
manufacture,  it  is  not  regarded  as  being  so  satisfactory  as  the  Grainger  shales, 
underlie  the  limestone  formation. 
In  the  Coal  Measures  of  the  Middlesboro  district,  immediately  west  of  Cumb 
Mountain,  shale  beds  occur  at  many  localities.  At  the  Harkness  Brick  Works,  8 
northwest  of  Cumberland  Gap,  some  of  these  Carboniferous  shales  have  been  ul 
Analyses  of  these  shales,  by  A.  11.  Phillips,  follow: 
Analyses  of  Carboniferous  shahs  used  at  Harkness  Brick  Works. 
Silica  (SiOa) 
Alumina  (A1203) 
Iron  oxide  I  I 
Lime  (CaO) 
ia    W'rXO) 
KaO) 
Soda    V'.'  i  
Carbon  dioxid 
Combined  water 
61. 14 
19.35 
5.89 
.93 
1.87 
3.07 
1.  54 
5.  80 
