466 Our Coal Supply and our Prosperity. [ Oct., 
especially in Mid-Cheshire ; but within this latter depth there are 
large areas in Leicestershire, Warwickshire, Staffordshire, Notts, 
and probably the eastern districts of Yorkshire, along a band of 
country ranging from the estuary of the Tees southward by York, 
and crossing the Humber near Goole. This tract is overspread by 
Liassic and Oolitic formations, containing the ironstone of the 
Cleveland Hills; and if Mr. Vivian’s somewhat sanguine views as 
regards depth be adopted, it would be quite possible to conceive of 
a shaft entering the ground at the outcrop of the Liassic ironstone, 
and penetrating to the underlying coal; the depth, however, would 
be considerably greater than 1,000 yards over the whole district. 
Into the overlying Permian and Triassic formations, collieries have 
already advanced to a considerable extent. The Magnesian Lime- 
stone of Durham, Yorkshire, and Notts has been and is being 
pierced by many shafts, while the water which saturates this and 
the underlying Permian Sandstone, and which at first was a formid- 
able impediment, is pumped for the supply of the towns. The 
New Red Sandstone along the southern margin of the Lancashire 
coal-field, as also that near Rugeley, Cannock Chase, and Ashby-de- 
la-~Zouch have been pierced, and the underlying minerals won ; while 
in Somersetshire, owing to the thinness of the Triassic rocks, the 
Lias itself has been pierced by several collieries. Thus has been 
commenced a phase of coal-mining under the overlying geological 
formations, destined at no distant day to assume much larger 
proportions. 
While maintaining that there are very large areas—larger in 
fact than the areas of the English and Welsh coal-fields themselves 
—which contain coal overlaid by Permian, Triassic, and Liassic 
formations, we at the same time hold that this area has been over- 
estimated both by Mr. Vivian and those who have given an opinion 
on the subject. We concur with Mr. Jukes* in his view that 
the coal-measures were never deposited in that part of Worcester- 
shire south of the Clent and Licky Hills; and Mr. Hull has shown 
that, both from the thinning away of the coal-measures towards 
the south-east, and from the uprising of the Old Silurian rocks 
during the coal period, we are not to look for coal under the eastern 
counties of England. The discovery of slate rock at a depth of 
1,035 feet at Harwich, beneath the Cretaceous formations, is 
significant evidence of the credibility of these conclusions. 
The foregoing considerations lead us to pause for a moment in 
our inquiry, and to ask our readers whether, provided these views 
be correct, all calculations as to the probable duration of our coal 
supply are not at once invalidated by the fact that it is at present 
beyond the power of any living person to estimate what that supply 
*<The Geology of the South Staffordshire Coal-field.’ Mem. Geol. Survey. 
Second edit. Le 
