318  CONTBIBUTIONS    TO    ECONOMIC    GEOLOGY,   1903.  [bull.225. 
Middlt  block.-  I  fnder  I  his  heading  is  included  all  that  portion  of  the 
field  which  lies  between  Big  and  Whiskey  runs.  Sections  at  all  of 
the  working  hanks  can  not  be  given,  and  four  or  five  will  be  enough 
to  show  the  variable  characters  of  the  bed. 
Twenty-five  years  ago  the  local  trade  about  Elders  Ridge  was  sup- 
plied by  a  pit  on  the  H.  Ewing  farm.  This  coal  pit  was  a  short  dis- 
tance cast  of  the  Simon  Townsend  bank  (No.  7).  Here  the  bed  is  at 
its  thickest,  and  the  following  detailed  section  was  measured  by  the 
second  geological  survey  of  Pennsylvania: 
Section  at  the  Ewing  coal  lunik. 
Roof  division:  Ft.  Tn. 
Slate  and  coal 2  0 
Coal 0  7 
Slate 0  1 
Coal 0  2 
Slate  and  clay,  main  parting  _ . . 0  10 
Coal 1  6 
Slate --- 0  1 
Coal,  slaty 0  10 
Slate 0  1 
Coal 1  3 
Slate,  4  inches  to 1  6 
Coal 1  6 
Slate,  j  inch  to 0  3£ 
Coal 1  8 
Slate  
Total 12      4£ 
The  seam  shows  more  slate  partings  than  is  usual,  and  the  coal  in 
the  different  benches  is  said  to  be  slaty  and  poor.  This  much-parted 
condition  of  the  seam  may  be  local,  however. 
The  Pittsburg  coal  is  mined  on  Harper  Run  by  John  Hart.  A  sec- 
tion obtained  there  shows  all  of  the  bed  except  perhaps  a  thin  layer  in 
the  roof  shales.     The  following  measurement  was  made: 
Section  at  John  Hart  coal  hank. 
Ft,     Tn. 
Coal 0  10 
Shale 1  0 
Coal 4  0 
Shale 0  1 
Coal 1  2 
Shale 0  6 
Coal 1  8 
Total 9      3 
At  the  new  mine  of  the  Pittsburg  Gas  Coal  Company  a  measure- 
ment was  made  in  heading  No.  2.  This  mine  is  just  across  the  run  from 
the  bank  mentioned  above,  but  shows  fewer  partings.     The  section  is: 
