462 Our Coal Supply and our Prosperity. [Oct., 
McCulloch of the yield in 1840 at 30,000,000 tons, the total 
increase in 25 years will have been about 68,000,000, or at the rate 
of 2°6 millions per annum, which was nearly the amount assumed 
by Sir W. Armstrong (2,750,000 tons per annum). 
There is no probability of absolutely new sources of supply 
beyond these coal-fieids and their marginal tracts of Permian and 
New Red Sandstone. The geological evidence is against the sup- 
position of the existence of coal under the Eastern and Southern 
counties of England, with the possible exception of a narrow 
trough under the cretaceous rocks of the Thames valley. This 
is owing to the uprising of the Silurian rocks beneath the newer 
formations of which we have indications in Leicestershire, War- 
wickshire, South Staffordshire, and Shropshire. It is also certain 
that the Somersetshire coal-fiell terminates to the eastward under 
the lias, and is disconnected with any possible coal-strata under the 
Thames valley. 
There are several coal-fields of which it may be confidently 
affirmed that they have passed their prime, and are verging on 
decay ; of these the coal-fields of Coal-brook Dale, in Shropshire, 
the Flintshire, and the South Staffordshire are the examples. 
There are others which have nearly attained their meridian of 
development, such as Durham, Lancashire, Warwick; Yorkshire, 
Derbyshire, and Notts (all one); and there are others which are 
capable of considerable increase in the amount of their yield; of 
which the examples are Denbighshire, North Staffordshire, Leicester- 
shire (especially under the adjoming New Red Sandstone areas), 
Forest of Dean, and South Wales. Some districts of the Scottish 
coal-fields have also seen their best days, but on the whole the 
resources of the coal area of Scotland are on the same parallel as 
those of England and Wales.* 
The following is a summary of the outputs of the coal-fields 
from the mineral statistics of Great Britain for 1865.t 
Tons. Condition. 
1. Durham and Northumberland. . . . . 25,032,694 (increasing) 
2.' Cumberland 2° 5 s09s) wa 2) se 1, 14311037 (Gmcreasina) 
5. Yorkshire, Derbyshire, and Notts. . . . 15,046,350 (increasing) 
4: elcestershine saint i oes dias. es colseneec ihe 965,500 (increasing) 
Do: Warwickshire, Were) a. as ee 859,000 (increasing) 
6. Staffordshire and Worcestershire . . . . 12,200,989 (increasing) 
7. Lancashire ‘ j; . . . 11,962,000 (increasing) 
8. Cheshire } ened 1 850,000 (increasing) 
* An interesting inquiry into the actual quantity of gas-coal, or cannel, in the 
United Kingdom, has just been concluded by Mr. R. Hunt, F.R.S., and is addressed 
to Messrs. Baxter, Rose, Norton, and Co., of Westminster. From this it appears 
that the total quantity of this valuable mineral is very limited; that the present 
supply of 1,418,176 (1865) might be increased to 3,172,000, which would go far 
towards exhausting the mineral in a period considerably less than half-a-century. 
+ Mine-al Statistics. R. Hunt, 1865. 
