I  have  pointed  out  that  the  Commissioners  based  their
Report  on  the  assumption  that  seams  of  coal  could  be
practically  worked  down  to  depths  of  4,000  feet  where  the
natural  temperature  would  be  116**  Fahrenheit.  This  tem-
perature, calculated  upon  one  degree  for  every  60  feet  of
depth,  I  have  found  by  experiment  to  be  under  the  mark
and  requires  the  addition  of  one  degree  for  every  100  yards
of  depth,  so  that  at  4,000  feet  the  temperature  would
actually  be  nearly  130"  Fahrenheit.
Temperatvbes  taken  in  Plitogxd  Drill  Holes.
Name  of  Mine.
Theoretical
Temperature
due  to  depth

Douglas  Bank  (Arley  Seam).
86°

Abram  (Arley  Seam)

83°

Ditto

87°

Bosebridge  (Arley  Seam)    . ..
90°

^Ashton's  Moss  (4-feet  Seam).
100°

•Astley  Deep  Pit

96°

Alexandra

87°

Actual
Temperature.
Depth

91°        ....
740

89°       ....
686

94°       ....
768

.      93}°      ....
806

90°       ....
1033

.       88°       ....
961

88°       ....
755

*  It  is  not  clear  whether  the  temperatures  given  in  these  oases  were  taken  in  the  air
at  face  or  in  drill  holes.
387


TSICPERATUBB    OF    AlB    IN    FaGB    OF    WOBEXNGS,    THE    W

PLACES    BEnrO    SELEOTED.
Name  of  Mine.
Pemberton

Tempera-
ture.
81°

Depth  from
surface  in  yarda.
592        ...
Diftance  from
down  cast  shaft.
•                                                   •    •   •   ■

Abram

81°

758       ...
750

Abram

84°

686

1200

ThiVinfifilH

86°

1056

Bottom  of  dip.
Not  stated.
Alexandra

82°

755       . ..
Aflhton'sMoss..
Duldnfield  ....
86°

. .       87°

. .     1019       . ..
961       . ..
Top  of  No.  2  level
North  Side  Dip.
Douglas  Bank
Douglas  Bank
Douglas  Bank

65°

.       68°

. .       75°

740       ..
740       ...
750         ..
