LUPTON : SOME NOTES ON THE YORKSHIRE COALFIELD. 435 
at the now closed Newton Colliery, near the northern outcrop, the 
Warren House coal, which corresponds to the Barnsley bed, lies about 
500 feet below the sea level, giving a dip of 1,300 feet in ten miles 
from north to south. Going further south, the coal rises from South 
Kirby to Denaby Main, where, on the corresponding line of longitude, 
this coal is only 1,200 feet in depth. It is, therefore, evident that 
South Kirby is very nearly in the centre of a trough from which the 
coal rises north and south and west. There will also be from South 
Kirby a gradual eastwardly dip. 
The deepest shaft yet sunk to the Barnsley bed is that at Cadeby, 
about four and a-half miles south-west of Doncaster, where the coal 
is 750 yards deep. Judging from the rate of inclination down to the 
east, proved by the dip of the coal from the outcrop near Barnsley to 
Cadeby, it is probable that the depth under Doncaster will be about 
1000 to the Barnsley bed, and it may be a little more and it may be 
a little less. 
The total thickness of the Yorkshire Coalfield yet proved down 
to the Millstone Grit is about 4,700 feet, or in round figures 5,000 
feet. There are altogether about fifty seams of coal, and the total 
thickness is over 100 feet. 
At the present time coal seams are worked in Yorkshire varying 
in thickness from about 14 inches to 10 feet. A 14-inch coal can 
only be profitably worked under peculiar local conditions, and it is 
only in a few localities that 10 feet of coal are found workable in one 
seam. In Yorkshire any coal under 3 feet is classed as a thin seam. 
The Coalfield is roughly divided into two districts by a line of 
longitude passing through Leeds. Westward of this line of longitude 
is the thin coal district and eastward is the thick coal district. In 
the thin coal district the coal is got in the proximity of the town and 
factory where it is used, though the working cost is pretty high, 
amounting to 7s. or 8s. a ton. In the district to the east the coal 
seams are 3 feet and upwards and the cost of working is greatly 
reduced, but the larger collieries have to send most of their coal 
some distance by railway or canal. Before this Coalfield is exhausted 
every seam of coal over 4 inches in thickness will be worked, and in 
n 
