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worked in the coal district of Yorkshire, and these are nine 
in number : — 
1. The Ironstone above the Aston Common coal, near 
Rotherham. 
2. The Ironstone above the Abdy or four foot of Tinsley 
Park, near Rotherham. 
3. The Ironstone above the Kents thin coal, in Tinsley Park, 
near Rotherham. 
4. That above the Swallow wood coal, by Earl Fitzwilliam, in 
Tankersley Park. 
5. The Tankersley or Muscle Band Ironstone, above the 
Upper Flockton coal. 
6. The Black Mine, above Park Gate coal. 
7. That above the Thorncliffe thin coal. 
8. The Clay Wood Mine, above the Silkstone coal. 
9. That above Black Bed of Low Moor. 
Of these the most valuable and extensively worked mine 
is that above the Black bed of Low Moor, wrought around 
Bradford, at Bowling, Low Moor, and Bierley. It yields 
about 1,000 tons per acre, and affords the chief supply of 
Ironstone in that locality. Its thickness, however, is 
variable, near Wike becoming so thin as to " set up" only 
seven inches, and it is sometimes intercepted altogether by 
a stone rock which takes its place. Its extent from Brad- 
ford, south, is only six or seven miles. The coal seam above 
which it lies, identical with the Shelley or Cumberworth 
bed, is, however, prolonged southwards nearly to Sheffield ; 
and Lord Wharncliffe a few years ago at my suggestion 
sought for at considerable expense this Ironstone, but was 
disappointed. This Ironstone, therefore, is variable in 
thickness, limited in extent, and frequently cut off or 
interrupted in its course by sandstone rock, and, when 
thickest, yields only 1,000 tons per acre. 
F F 
