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The iron-ore outcroppings are ill defined in the Lydbrook 
Valley, also to the North of Joyford, Farmers’ Folley, The 
Hobbles, and further to the North-West, where apparently it 
must have curved to the Slaughter House. The iron-ore field 
between the two last preceding mentioned places seems also to 
have projected in the form of a horse-shoe, but as the out- 
croppings cannot be traced, how far this projection extended 
cannot be determined. The irregular form of the Mineral 
Basin existing in the Northern portion of the Forest, leads to 
the inference that the limestone and iron-ore measures once 
extended over a considerable area Northwards, also towards 
the East and West, and that the whole has been removed by 
the natural influences previously indicated. Some portions, 
however, had a greater tenacity and power of resistance than 
’ others. 
When the Pumping Pit at Wigpool Iron Mine was sunk, 
a thin seam of coal, believed to be the Trenchard, was dis- 
covered at about 15 yards from the surface, and proved to be a 
good steam coal, but the roof consisted of hard clod, containing 
water, rendering it difficult and costly to work; consequently it 
was abandoned. At a little distance to the South of the 
Pumping Pit, a smaller shaft was sunk to a depth of 150 
yards, but as the measures were much confused the seam of 
coal could not be traced. 
Considering that this patch of coal is situated at a distance 
of about 14 miles from the well-known outcroppings of the 
Trenchard seam on Harrow Hill, and at comparatively such a 
short distance from the outcroppings of the iron-ore measures, 
it is highly probable that the seam of coal in question is not 
identical with the Trenchard, but is more likely to belong to 
the Millstone Grit series, and possibly may have had some con- 
nection with the seam of coal at Howell’s Hill. At all events 
this is the most North-Westerly point in the Dean Forest 
Mineral Basin where coal has been discovered. Iam of opinion 
that seams of coal existed in the Millstone Grit measures over 
the entire Forest area, and this idea seems to be corroborated 
by the fact that in other English coal fields the Millstone Grit 
