32 Original Articles. [Jan. 
area of the coal-field is 80 square miles, and the available supply 
about 400 millions of tons, to which a very large addition must be 
made for the quantity underlying the Permian formation. In 1861 
the produce of this coal-ficld was only 647,000 tons, which cannot be 
said to be in due proportion to the resources. 
The small and but slightly productive districts of Shrewsbury, the 
Forest of Wye, and the Clee Hills, do not require special notice here, 
further than to intimate their existence. 
SouTHERN CoAL-GROUP. 
Forest of Dean Coal-basin.—In structure, this is a more perfect. 
basin than any in Britain, as the strata everywhere dip from the cir- 
cumference towards the centre (Fig. 1). It is by no means opened up to 
the extent of its capabilities, and for the most part presents the aspect of 
rich forest scenery, with only an occasional coal-pit chimney at wide 
intervals rising in the midst of the trees. Its area is 34 square miles, 
and it contains about 560 millions of tons of available coal. The 
annual produce is about 1,000,000 tons, which in a few years will 
be considerably extended by the introduction of railways now in pro- 
cess of construction. 
Bristol and Somersetshire Coal-basin.—The greater portion of this 
basin is uncomformably overlaid by a newer formation of Trias, through 
which the coal-measures only appear at intervals ; yet its general form 
has been pretty well ascertained by means of collieries and borings, 
Including the parts occupied by Red Marl and Lias, the area is not 
less than 150 square miles, with 51 seams of coal distributed through 
5,000 feet of strata. Of these seams, however, only 20 are of a thick- 
ness of 2 feet and upwards, and owing to some special physical impe- 
diments (such as the presence of the “ Pennant Grit”), very large 
deductions require to be made before arriving at the available supply. 
This quantity I do not place at a higher figure than 2,000,000,000 
tons. The produce for 1861 was 1,025,525 tons. 
South Wales Coal-basin.—The greatest of our coal-basins is the last 
but one to be described. It is truly an astonishing reservoir of mine- 
ral fuel, whether we regard it for its actual area, not less than 910 
square miles; the enormous thickness of the strata stored with coal, 
reaching 10,000 feet; the vertical accumulation of coal, stated by one 
authority to be from 70 to 100 feet in thickness ;* or lastly, from the 
symmetrical form of its outline, which is nearly that of a pear. It is, 
in fact, an elongated basin or trough in which the strata dip towards 
the central axis, that axis itself at the same time coinciding with a 
great upheaval of the strata in the form of a roll or anticlinal. The 
coal-field is divided into three districts: the west, yielding anthracite ; 
the centre, steam coal; and the east, bituminous coal. The richer 
beds lie near the bottom, and these are often placed within reach of 
mining operations by the great depth of the valleys, which penetrate 
for miles into the central high-lands, laying bare the strata many hun- 
dred feet. 
* Mr. H. H. Vivian, ‘Speech on the Coal Clause,’ House of Commons, 1861. 
