198  CONTRIBUTIONS   TO    ECONOMIC   GEOLOGY,    1907,    PART   II. 
CHEMICAL   PROPERTIES. 
The  chemical  character  of  these  coals  is  indicated  by  the  subjoined 
analyses : 
Analyses  of  coal  samples  from  Basin,  Wyo.,  and  Bridger,  Mont.,  coalfields. 
[F.  M.  Stanton,  chemist  in  charge.] 
Basin,  Wyo. 
(Fort 
Union) . 
Bridger,  Mont.  (Eagle). 
Labor 
5778. 
5495. 
3955. 
3956. 
5508. 
3954. 
Sampl 
e  as  received: 
Moisture 
14.94 
33.43 
37.90 
13.73 
1.76 
5.68 
53.27 
1.02 
24.54 
5,281 
9,506 
14.83 
26.93 
44.89 
13.35 
.33 
5.61 
57.05 
.91 
22.75 
5,576 
10,037 
8.47 
31.47 
41.88 
18.18 
.84 
8.70 
34.03 
49.07 
8.20 
.63 
9.76 
27.66 
46.16 
16.42 
.63 
5.09 
56.19 
1.01 
20.66 
5,686 
10,235 
8.93 
M 
Volatile  matter 
33.43 
^ 
Fixed  carbon 
46.92 
Ph 
fAsh 
10.72 
[  \Sulphur 
.61 
+» 
P 
Ca 
Br 
Loss  of  moisture  on  air  drying 
4.60 
8.80 
3.20 
3.10 
3.70 
3.60 
Air-dr 
ted  sample: 
Moisture 
10.84 
35.04 
39.73 
14.39 
1.84 
5.42 
55.84 
1.07 
21.44 
5,536 
9,964 
6.61 
29.53 
49.22 
14.64 
.36 
5.08 
62.55 
1.00 
16.37 
6,114 
11,005 
5.44 
32.  51 
43.27 
18.78 
.87 
5.78 
35.12 
50.64 
8.46 
.65 
6.29 
28.72 
47.94 
17.05 
.65 
4.86 
58.35 
1.05 
18.04 
5,904 
10,629 
5.53 
Volatile  matter .  „ 
34.68 
Fixed  carbon 
48.67 
^ 
(Ash 
11.12 
\Sulphur 
.63 
+s 
p 
Ca 
Bi 
lories 
5778.  Seven  miles  southeast  of  Basin,  Wyo.    Collected  by  C.  A.  Fisher,  1907. 
5495.  One  mile  west  of  Bridger,  Mont.    Collected  by  C.  W.  Washburne,  1907. 
3955,  3956.  One  mile  west  of  Bridger,  Mont.    Collected  by  N.  H.  Darton,  1906. 
5508.  Coalville,  Mont.    Collected  by  M.  A.  Pishel,  1907. 
3954.  One  mile  west  of  Fromberg,  Mont.    Collected  by  N.  H.  Darton,  1906. 
An  air-dried  sample  of  Foft  Union  coal  has  a  calorific  value  of  9,964 
British  thermal  units;  similar  samples  of  Eagle  coal  show  11,005  and 
10,629  British  thermal  units.  The  superiority  of  the  Eagle  coal  is 
further  indicated  by  the  higher  content  of  fixed  carbon  and  lower 
content  of  sulphur. 
CONDITIONS   OF  MINING. 
The  gentle  dip  of  the  minable  coal  in  these  fields  is  favorable  to 
development.  The  amount  of  water  is  not  great,  but  in  some  locali- 
ties, especially  in  the  Silvertip  field,  it  necessitates  pumping.  Near 
Fromberg  and  Coalville  the  amount  of  water  that  enters  the  mines  is 
so  small  that  it  is  drawn  out  in  water  cars  attached  to  the  regular 
trips.  Dust  is  always  present  in  the  dry  mines,  but  not  in  dangerous 
quantities.  Gas  is  not  troublesome.  Open  lamps  are  used  in  all  the 
mines,  but  there  have  been  no  explosions.  Practically  no  mine  tim- 
ber is  produced  in  the  region.  Yellow  pine  and  fir  shipped  in  from 
the  outside  cost,  in  1907,  about  $25  per  1,000  feet  B.  M. 
