bukchard.]     LIGNITES  OF  MIDDLE  AND  UPPER  MISSOURI  VALLEY.      283 
amount  to  nearly  as  much  as  the  value  of  the  fuel  removed.  No  satis- 
factory roof  has  been  found  over  any  of  the  Dakota  County  lignites. 
Thus  there  are  two  hindrances  to  practicable  mining  of  the  lignite 
where  found  in  its  nearest  approach  to  sufficiency,  and  these,  together 
with  its  doubtful  fuel  value  and  its  limited  quantity,  constitute  good 
reasons  why,  at  present,  such  deposits  in  this  region  must  be  con- 
sidered as  having  no  commercial  value  as  a  general  fuel  supply. 
Many  writers  have  suggested  that  lignites  and  other  inferior  car- 
bonaceous deposits  in  the  United  States  might  be  made  productive  by 
briquetting.  Economic  conditions  do  not  yet  warrant  such  an  attempt 
in  this  region,  but  it  may  be  considered  as  a  remote  future  possibility. 
Dakota  County  is  well  situated  for  manufacturing  and  distributing 
purposes,  and  the  lignite  areas  are  easily  accessible  for  railroad  spurs. 
Certain  thoughts  suggested  by  the  conditions  may  be  worthy  of  con- 
sideration. If  the  bed  of  lire  clay,  apparently  so  constant  beneath 
the  lignite,  could  be  mined  with  it,  the  latter  might  be  used  near  by 
to  burn  tire  brick  from  the  clay.  The  lignite  might  be  thus  used 
directly  as  a  fuel  or  be  first  converted  into  fuel  gas.  Some  of  the 
sands  of  the  Cretaceous  may  be  found  to  be  suitable  for  the  manufac- 
ture of  glass.  A  gaseous  fuel  is  best  adapted  to  such  an  industry. 
Thus  in  more  than  one  way  the  high  gaseous  content  of  the  lignite 
might  be  utilized  in  the  immediate  vicinity;  but  not  until  thorough 
tests  have  shown  such  utilization  to  be  practicable  can  any  encourage- 
ment be  offered  for  the  production  of  this  lignite. 
LIGNITE  IN   NORTH  DAKOTA. 
Contemporaneously  with  the  writer's  study  of  the  Nebraska  lignites 
the  State  geological  survey  of  North  Dakota  was  carrying  on  prelimi- 
nary investigations  of  the  fuel  resources  of  that  State.  From  the 
comprehensive  report  by  Doctor  Wilder a  a  few  facts  are  here  pre- 
sented, some  of  which,  aside  from  their  local  significance,  have  an 
important  bearing  on  the  general  problem  regarding  the  utilization 
of  lignite  as  a  fuel. 
Boundaries  of  the  lignite  area. — Workable  seams  of  lignite  have  been 
found  scattered  throughout  the  whole  western  half  of  the  State  and 
beyond  its  boundaries  to  the  north,  west,  and  south.  The  eastern 
limit  of  workable  seams  of  lignite  is  roughly  along  a  line  beginning  at 
the  northern  boundary  of  the  State,  10  miles  east  of  Mouse  River, 
longitude  101°  45'  W. ,  and  extending  thence  to  the  west-central  part 
of  Wells  County,  at  latitude  47°  30'  N.,  longitude  100°  W.,  thence 
south  to  the  southern  boundary  of  the  State.     The  Turtle  Mountains 
"Wilder,  Frank  A.,  The  lignite  coal   fields  of  North  Dakota:  Second  Biennial  Report  of  the  State 
Geological  Survey  of  North  Dakota,  1903. 
