342  CONTRIBUTIONS    TO    ECONOMIC    GEOLOGY,   1903.  [bull.  225. 
Branch.  The  history  of  this  development  could  not  be  obtained,  but 
it  has  not  been  worked  for  at  least  eight  years.  Considerable  coal  is 
still  present  on  the  dump,  and  from  these  small  fragments  a  sample 
was  obtained,  which  yielded  analysis  No.  3. 
It  is  interesting  to  note  that  weathering  has  had  no  appreciable 
effect  upon  this  coal.  The  amount  of  moisture  is  no  greater  than 
that  contained  in  the  samples  obtained  from  the  Chappelle  shaft,  but 
the  fuel  value  is  somewhat  less,  presumably  due  to  the  increased  per- 
centage of  volatile  hydrocarbons.  This  increase  is  not  due  to  weather- 
ing, but  depends  upon  the  original  composition  of  the  coal. 
From  the  above  analyses  it  is  apparent  that  the  coal  of  this  field,  so 
far  as  it  is  represented  by  the  samples  taken,  is  not  an  anthracite  and, 
in  fact,  it  is  doubtful  if  it  falls  within  the  class  of  semianthracites. 
According  to  the  classification  proposed  by  Persifor  Frazer,  jr.,a  and 
generally  adopted  by  the  geologists  of  the  second  geological  survey  of 
Pennsylvania,  the  fuel  ratio  (per  cent  of  fixed  carbon  divided  by  per 
cent  of  volatile  hydrocarbons)  of  hard,  dry  anthracite  ranges  from  100 
to  12;  semianthracite,  from  12  to  8;  semibituminous,  from  8  to  5,  and 
bituminous  (disregarding  lignites),  from  5  to  0. 
Fuel  ratios  of  6.92,  8.13,  and  6.20,  as  shown  by  the  analyses  on  page 
311,  indicate  that  the  coal  belongs  close  to  the  dividing  line  between 
the  semibituminous  and  semianthracite  classes  and  that  it  can  not  com- 
pare with  Pennsylvania  anthracite,  the  fuel  ratio  of  which  is  always 
greater  than  12. 
Although  this  coal  is  not  an  anthracite,  it  may-  have  considerable 
value  as  a  fuel  since  its  low  percentage  of  volatile  hydrocarbons  prob- 
ably renders  it  nearly  smokeless.  Its  commercial  value,  however,  will 
depend  largely  on  the  condition  in  which  it  reaches  market  and  the 
amount  of  impurities  that  it  carries.  The  crushed  coal  on  the  eastern 
limb  of  the  syncline  is  in  poor  condition  for  shipment,  but  it  seems 
possible  that  in  the  center  of  the  basin  the  coal  may  be  less  badly 
crushed  and  that  it  may  be  mined  in  sizes  that  will  command  good 
market  prices. 
Where  the  coal  bed  is  undisturbed  the  shale  partings  are  easily: 
removed  during  the  process  of  mining,  but  where  it  is  crushed  so  badly 
as  it  is  on  the  eastern  limb  of  the  syncline  the  separation  of  the  shale 
fragment  from  the  coal  is  a  difficult  matter.  Owing  to  the  low  specific! 
gravity  of  the  coal,  separation  may  be  affected  by  washing,  as  suggested 
by  Mr.  Griffith. » 
DEVELOPMENT   OF  THE  FIELD. 
With  the  exception  of  the  mines  that  were  formerly  worked  in  the 
bottom  of  the  syncline  south  of  the  Meadows  road  all  the  develop- 
aFrazer,  iVrsifor,  jr.,  Classification  of  coals:   Second  Geological  Survey  of  Pennsylvania,  Report 
M  M.  1S79,  p.  144. 
l>  Jour.  Franklin  Inst.,  vol.  154,  1902,  p.  438. 
