mystery; but, that it has taken far longer to
elaborate than the human race has done to
complete thus far its history on the earth, there can be
no doubt. If coal be now forming, man is not
assisting, and knows not how to assist, in the operation.
Nor is there any great probability that large
deposits of undiscovered mineral fuel exist near
the surface of the earth in any part of our
country. Doubtless there is coal, and perhaps
in large quantity, under certain of the rocks that
have not yet been sunk through. The general
limits, however, even of these unseen stores are
pretty well known, and they form a reserve
which will not be touched till the cost of extraction
of known deposits is much increased, or
the expense of opening out a coal-field at
considerable depth much reduced.

Keeping these considerations in view, we may
proceed to consider the extent of our known
resources and the prospect they offer of
permanence. For this purpose let us estimate the
area of country occupied by those rocks amongst
which coal may be expected to be found. The
districts of this kind are called coal-fields, and in
all of them coal-husbandry has advanced pretty
rapidly within the last few years.

These districts are numerous and extensive.
The most important are thus described: 1. The
Newcastle coal-field in the counties of Northumberland
and Durham. 2. The Lancashire, including
Flintshire and North Staffordshire. 3. The
Yorkshire (East Riding), including Nottinghamshire
and Derbyshire. 4. The South Staffordshire.
5. The Somersetshire and Gloucestershire,
including the Forest of Dean. 6. The South
Wales. Besides these, coal underlies parts of
the counties of Cumberland, Westmoreland,
the West Riding of Yorkshire, Shropshire and
Worcestershire, Warwickshire and Leicestershire.
There are in Scotland a number of
detached coal-fields, of which that in the valley of
the Clyde and Lanarkshire is the chief. Ireland
is not without coal, but the quality is poor, and
the position of most of the fields inconvenient.

The Northumberland and Durham district
of coal-fields is a compact area of half a million
of acres, in which as many as eighteen beds
are known which are thick enough to pay
for working; but they are not all present
on the same spot, and the thickest does not
exceed seven feet. It is calculated, and with some
approach to precision, that the average thickness
of coal over the whole field is about twelve feet
(including all the seams), giving a total
estimated content of about ten thousand millions
of tons. If only one fourth of this be obtainable,
there should still be two thousand five
hundred millions of tons, of which, perhaps, five
hundred millions are already taken: leaving thus
in this one field about two thousand millions, or
twenty-five years' supply for the whole kingdom.

But, the Newcastle coal-field is neither the
largest nor the most productive of our districts,
although it is the one that has been longest
opened. The Lancashire district is as large,
and has a far greater thickness of coal. The
Yorkshire is larger, but the coal-beds are not so
numerous, though some are thicker. The South
Staffordshire is small, but the thickness of the
coal exceedingly great, amounting in the same
mine to between thirty and forty feet. The
Somersetshire contains a large number of beds, and
the total thickness of the coal is very great, but
the area is only one half that of the Newcastle:
while the South Wales, with a much greater
available area, has thicker beds, more of them,
and altogether a much larger supply. The
Scotch coal-fields occupy together at least three
times the space of the Newcastle, and the
thickness of available coal in them is more than
double; the thick seams being also double.

Bringing these figures together we shall find
that the whole area of known coal-fields in
England, Wales, and Scotland exceeds four millions
of acres, or six thousand two hundred and fifty
square miles; that, over this area, there is an
average thickness of coal which cannot be
estimated at much less than fifteen feet, or five yards,
and that, therefore, the estimated quantity of
coal is equivalent to a bed whose surface
occupies thirty-one thousand two hundred and
fifty square miles, one yard thick.

The eighty millions of tons annually
consumed at present, would be equivalent to an
area of nearly fifty square miles, one yard thick;
and thus an estimate of six hundred years
for the duration of our coal, at the present
rates of consumption, would seem to be justified.

But, there are certain very important deductions
that require to be made. One, indeed, has
already been allowed for in our estimate, as
the actual extent of country shown on our
geological maps as coal-bearing amounts to
about twelve thousand square miles, and the
calculations of acreage made do not much exceed
half that amount. Fifty per cent, therefore,
has already been deducted for unproductive
portions of the fields where the coal is injured and
unobtainable, whether from faulted ground,
inconvenient depth, or patches of bad quality.

We must, however, make a further large
deduction, if we would fairly approach to a
solution of the practical question. From the total
acreage of coal lands, a coal surveyor, in
estimating the value of a district, would deem it
fair, not only to strike off fifty per cent for the
injured and faulted coal, and the deep parts of
the beds, but he must make a further allowance for
what is left underground to support the roof,
and for the loss of upper beds when the lower
ones are first extracted. Our thirty-one
thousand two hundred and fifty square miles of coal
one yard thick, will thus dwindle down to twenty
thousand.

Still, there remains a supply equivalent to four
hundred times that which is now annually
extracted; but, as all these calculations are made
on the assumption that no coal has been
removed, and, as our coalowners have been
doing their best, not only in the way of fair
extraction, but very unfair destruction, for many
years, we fear that at least a century more must
be struck off from this period if we would fairly
estimate our resources. The consumption,