ON THE EXHAUSTION OF OUE COAL. 
297 
from which tlie matter forming those rocks had keen re- 
moved. This signifies, however, but little in the present 
inquiry. Some few persons, indeed, may be found who 
believe that coal may extend under the eastern and southern 
counties ; but such a vague hypothesis cannot be entertained. 
We have only to deal with the coal-fields proper which are 
known, and their probable extension beyond the limits at pre- 
sent explored by the colliery operators. 
The annexed section of the Forest of Dean coal-field shows 
a true coal basin. The South Wales coal-field is equally a 
basin ; but this is not so evident in some others. 
The difficulty, the uncertainty, which surrounds the u Coal 
Question 39 meets us at the first step. The area occupied by 
coal within the Carboniferous deposits has never yet been 
determined with that accuracy which is necessary for computing 
the quantity of coal now, or at any time, existing. If we ex- 
amine all that has been written on the subject, we shall find a 
strange want of agreement between the writers on this, the 
simplest element in the problem they pretend to solve. The 
beautiful maps of the Geological Survey give the Coal Measures 
with great accuracy, and in remarkable detail trace out the 
outcrops of the beds of coal ; thus furnishing a considerable 
amount of exact knowledge upon which an inquiry might be 
based; but this has not hitherto been done. On those maps, 
also, we have numerous “ faults ” carefully laid down, showing 
the disturbances which have dislocated the coal-beds ; removing 
some so far below the surface that they are never likely to be 
reached, and lifting others so that they have been brought 
within the range of water action, and thus worn down, and 
removed for ever. 
2. In reply to the second question, it will be admitted on 
all hands, that we have no means of arriving at any correct 
knowledge of the quantities of coal which have been 
removed. Until a very recent period, scarcely any plans of 
the subterranean works were kept ; and, indeed, until after 
the passing of the Inspection Act, there was nothing approach- 
ing to a regular system of recording the work done. Con- 
sequently, there are large tracts of country of which we know 
nothing, except that they have been worked by the old miners, 
in which coal may still exist, but which is lost to us for ever. 
This, however, is. not so all-important. 
3. What is the total quantity of workable coal remaining in 
the collieries now at work ? is the great question of which we 
have to seek a solution. 
This may be determined within very small limits of error ; 
but it will require a large expenditure of time, and conse- 
quently of money. There are in the British isles 3,268 col- 
