calculated that with an increase of but one million and a half of tons
per annum—considerably less than even the average increase for the
preceding decade[6]—our coals would last us but a little more than
300 years. Mr. Stanley Jevons, in his masterly treatise on ‘The Coal
Question,’ adopted a mode of considering the increase, which has led
to an even more unpleasant conclusion than any hitherto obtained. He
observed that the quantity of coal raised in successive years is not
merely increasing, but the amount of increase is itself increasing.
‘We, of course, regard not,’ he said, ‘the average annual arithmetical
increase of coal consumption between 1854 and 1863, which is 2,403,424
tons, but the average rate per cent. of increase, which is found by
computation to be 3·26 per cent.’ That is to say, for every hundred
tons of coal consumed in one year, 103¼ tons, or thereabouts, would
be consumed in the next—taking one year with another. Without entering
into technicalities, or niceties of calculation, it is easy to show
the difference between this view of the matter and a view founded only
on the average increase during so many years. Consider 10,000 tons of
coal sold in one year, then Mr. Stanley Jevons points out that instead
of that amount, 10,326 would be sold in the next; and so far we may
suppose that the other view would agree with his. But in the next, or
third year (always remembering, however, that we must take one year
with another), the increase of 326 tons would not be merely doubled,
according to Mr. Stanley Jevons; that is, the consumption would not be
only 10,652 tons:—the 10,000 of the second year would be replaced by
10,326 tons in the third year, and the remaining 326 would be increased
by 3¼ tons for each hundred, or by rather more than 10½ tons;
so that in all there would be 10,662¼ tons, instead of 10,652.
Now the difference in this third year seems small, though when it is
applied to about nine thousand times 10,000 tons it is by no means
small, amounting in fact to 95,000 tons; but when the principle is
extended to sequent years its effects assume paramount importance. The
small increase is as the small increase of a farthing for the second
horseshoe-nail in the well-known problem. The effects, after a few
years have passed, correspond to the thousands of pounds by which the
last shoe-nails of that problem increase the cost of the horse. As Mr.
Leonard Lemoran points out in the paper mentioned in the above note,
if the assumed rate per cent. of increase continue, ‘we should draw in
the year 1900 from our rocks more than 300 millions of tons, and in
1950 more than 2,000 millions.[7] About 300,000 miners are now (1866)
employed in raising rather more than 92 millions of tons of coals;
therefore more than eight million miners would be necessary to raise
the quantity estimated as the produce of 1950. One-third of the present
population of Great Britain would be coal miners.’ Or as Mr. Jevons
himself sums up our future, ‘If our consumption of coal continue to
multiply for 110 years at the same rate as hitherto, the total amount
of coal consumed in the interval would be 100,000 millions of tons.’
Now as Mr. Hull estimated the available coal in Great Britain, within
a depth of 4,000 feet, at 83,000 millions of tons, it followed that,
adopting Mr. Jevons’s mode of calculation, a century would exhaust
‘all the coal in our present workings, as well as all the coal seams
which may be found at a depth of 1,500 feet below the deepest working
in the kingdom.’ It should be added, however, that Mr. Stanley Jevons
mentioned 200,000 millions of tons as the probable limit of the coal
supplies of Great Britain.
The opinion of Mr. Jevons respecting the probable rate of increase
of our consumption was not accepted by the generality of those who
examined the subject in 1865 and 1866. There were some, indeed, who
considered that the assumption was ‘absurd in every point of view.’ In
one sense, indeed, Mr. Jevons himself would have been ready to admit
that his estimates would not be justified by the result. The observed
rate of increase could not possibly be maintained beyond a certain
epoch, simply because there would not be enough men to work the coal
mines to the extent required. But, regarding the increase as indicating
the requirements of the kingdom, it would matter little whether the
necessary supply failed for want of coal or for want of the means of
raising the coal. In other words, removing the question from the arena
of geological dispute, and considering only the requirements of the
country, we should have this disagreeable conclusion forced upon us,
if Mr. Jevons’s estimate is just, that England will not be able, a
century, or even half a century hence, to get as many coals from her
subterranean cellars as she will then require. She may have the coals,
but she will not have men enough to bring them to bank.
It is, perhaps, in this aspect, that the question assumes its chief
interest for us. Rightly understood, the statements of Mr. Jevons
were of vital importance; so important, indeed, that the nation
might have looked forward to the results of the Commission much as
a patient would await the physician’s report of the result of a
stethoscopic examination. The power of the nation residing—for the
nonce at least—in her coal, the enforced consumption of coal at a
rate which cannot be maintained (from whatever cause), means to all
intents and purposes the decline and approaching demise of England’s
power as a nation. Furthermore, apart from all inquiries such as the
Commissioners undertook to make, the mere statement of the successive
annual yields was to be looked upon as of vital interest, precisely as
the progressive waste of a consumptive patient’s strength and substance
suggests even more serious apprehensions than the opinion of the
physician.
I have said that many eminent authorities held that the rate of
increase assumed by Mr. Jevons would not actually prevail. But some
went farther, and questioned whether the average annual arithmetical
increase of the lately passed years would continue even for the next
few years after the publication of Mr. Jevons’s work. ‘Such a continued
increase as that, which has taken place during the last five years,’
wrote an excellent practical authority, ‘cannot continue for the next
ten years,’—far less, therefore, that increasing rate of increase which
Mr. Jevons had assumed. The same writer went farther even than this.
For, after pointing out that the exportation of coal would probably
be soon reduced, rather than undergo, as during the past, a steady
increase, he added that ‘on every side there were evidences of the
most decided character, warranting the supposition that the annual
exhaustion of our coal fields would not at any period much exceed the
hundred million tons which it had nearly reached’ (in 1866).
One of the most interesting questions, then, which the Commissioners
were called upon to decide was, whether, at least during the period of
their labours, the anticipations of Mr. Jevons would be fulfilled or
not. It is easy to compare his anticipations with those above quoted;
or rather, it is easy to determine whether Mr. Jevons’s theory of an
increasing increase, or the theory of a uniform average increase,
accords best with the experience of the last five years. To make the
comparison fairly we must adopt the figures on which his own estimate
was founded. We have seen that he rejected the annual increase of
2,403,424 deduced from the records of the nine preceding years, and
adopted instead an increase of 3¼ per cent. year by year, taking
one year with another. His own calculations gave for this year 1871
a consumption of 118 millions of tons,—an enormous increase on the
annual consumption when he wrote. According to the view he rejected,
the consumption for the year 1871 is easily computed, though slightly
different results will be obtained, according to the year we choose
to count from. The annual increase above mentioned gives an increase
of 24,034,240 tons in ten years, and if we add this amount to the
consumption in 1861 (83,635,214 tons) we obtain for the year 1871 a
consumption of 107,669,454 tons. On the other hand, if we add eight
years’ increase to the consumption of 1863 (88,292,515 tons), we
obtain 107,519,907 tons.[8] It will be seen that there is an important
difference between the consumption for 1871, as estimated according to
Mr. Jevons’s view, and according to the average rate of increase in the
nine preceding years. As the matter stood in 1865, the great question
concerning the consumption of the year 1871 would have been,—whether it
would be nearer 118 millions, the estimate of Mr. Jevons; or to 107½
millions, the estimate, according to the annual rate of increase;
or, lastly, to a number of tons, not much, if at all, exceeding 100
millions?
The answer of the Commissioners comes in no doubtful terms. Judging
from the consumption during the four years ending in 1870, the
estimated consumption for the year 1872 is no less than 115 millions,
an amount approaching Mr. Jevons’s estimate much more nearly than
could be desired. Indeed, if we consider the imperfect nature of the
statistics on which he founded his calculations, the agreement between
his estimate and the observed result must be regarded as surprisingly
close. Remembering the conclusion to which Mr. Jevons came with respect
to the period for which our coal stores would last, and noticing the
close agreement thus far between his anticipations and the result,
we can well understand the warning tone of the report issued by the
Commissioners. ‘Every hypothesis,’ they say, ‘must be speculative, but
it is certain that if the present rate of increase in the consumption
of coal be indefinitely continued, even in an approximate degree, the
progress towards the exhaustion of our coal will be very rapid.’ Let
it be remembered that the Commission was issued at the instance of
those who took the more sanguine view, and that it included within
its ranks such eminent authorities as Sir William Armstrong, Sir
Robert Murchison, Professor Ramsay, Mr. John Hunt, and others of like
experience in the subject under inquiry.
If, in the next place, we compare Mr. Jevons’s estimate of the
quantity of coal available for use with the result obtained by the
Commissioners, we find little to restore our confidence in the extent
of time during which our coal stores may be expected to last. We have
seen that 200,000 millions of tons had been supposed to be available;
but the Commissioners find that ‘we now have an aggregate of 146,480
millions of tons, which may be reasonably expected to be available
for use.’ Again, it had been supposed that our coal mines could be
worked to a depth of 4,000 feet, or to an even greater depth. ‘The
difficulties in the way of deep mining,’ wrote Mr. Lemoran in 1866,
‘are mere questions of cost. It is important to notice that the
assumption of 4,000 feet as the greatest depth to which coal can be
worked, on account of the increase of temperature, is purely voluntary.
The increase has been calculated at a rate for which there is no
authority; and while we are saying our coal-beds cannot be worked below
4,000 feet, a colliery in Belgium has nearly approached that depth, and
no inconvenience is experienced by the miners.’ But the Commissioners
state that at a depth of only 2,419 feet in the Rosebridge mine (the
deepest in England), the temperature is 94 degrees of Fahrenheit, or
within four degrees of blood heat. ‘The depth at which the temperature
of the earth would amount to blood heat,’ they add, ‘is about 3,000
feet.’ They express a belief that by the ‘long wall system’ of working
(a system as yet seldom adopted in the chief northern mines) it will be
possible to reach a depth of 3,420 feet before this heat is attained;
but it is by no means certain that this will prove to be the case.
On the other hand, it will be well to regard the more promising aspect
of the question.
We must not forget, in the first place, that in all matters of
statistical research there is room for misapprehension unless careful
attention be paid, not merely to the observed facts, but to the
circumstances with which those facts are more or less intimately
associated. If we consider, for example, the progress of the
consumption of our coal during the past fifteen years, we find that a
law of increase exists, which is, as we have seen, easily expressed,
and which, after being tested by a process resembling prediction, has
been singularly confirmed by the result. But if we inquire into the
various causes of the great increase in the consumption of coals, we
find that while those causes have been increasing in activity—so to
speak—to a degree quite sufficient to explain the observed consumption,
they are yet such as in their very nature must needs be unable to
pass beyond a certain range of increase. Thus the population of Great
Britain has been steadily increasing, and at present the annual
increase is itself increasing. Then the amount of coal used in inland
communication is increasing, not only on account of the gradual
extension of the railway network, but also on account of the increase
of population, of commerce, and so on. Again, our commerce with other
countries has increased with great rapidity since the year 1860, when
the French treaty came into operation, and it will continue to increase
with the increase of our population, of our means of communication
within our own country as well as with foreign countries, and so on.
But all these causes of increase are now growing in activity at a rate
which must inevitably diminish. Our population cannot increase beyond a
certain extent, because the extent of the country will suffice for but
a certain number of inhabitants. If emigration do not prevent increase
beyond that number, other causes will, or else a much more serious evil
than the exhaustion of all our coal stores awaits the country. Again,
the requirements of inland communication will before long be so far
met that no such rapid extension as is now in progress will be called
for. After convenient communication has been established between all
parts of the country—whether the process require the formation of new
lines or of new services—no important increase can be required. As
regards our commerce, its increase depends necessarily on the increase
at present going on in the requirements of the country. Year by year
Britain has a larger population, and the average requirements of each
member of the population are also increasing. But we have seen that
the increase of her population is necessarily limited; and although
the increase of the requirements of her people may not be (strictly
speaking) limited, yet it is manifest that, inasmuch as that increase
depends on causes which are themselves approaching a limit, its rate
must, after a time, continually diminish. Let it be understood that,
when I speak of the requirements of the population, I do not mean
only what they must obtain from other countries. The commerce of a
country is the expression of the activity with which the nation is
‘earning its living,’ so to speak, and in a given population there is
a limit to what is necessary for this purpose, precisely as there is
a limit to the sum which an individual person in any given state of
life requires for the maintenance of a given family. Indeed, although
such comparisons are not always safe, we may in this case compare
what may be called the commercial requirements of the nation with the
requirements of the head of the family,—a merchant suppose. There are
no limits to the degree of wealth which a merchant may _desire_ to
gain, but unquestionably there are limits to the income necessary to
maintain his house and family and mercantile position. Supposing he
were extending his gains far beyond his actual requirements, it would
by no means imply his approaching ruin that there was a demonstrable
limit to this extension. And in like manner, it would seem that, apart
from the limits set by nature to the extension of our population,
it need by no means be assumed that if our commerce showed signs of
approaching a limit, the downfall of England’s power would be at hand.
In fact, we cannot accept Mr. Jevons’s figures for distant epochs
without first inquiring whether it is likely that at those epochs the
circumstances on which the consumption of our coal depends will be
correspondingly changed. Supposing that 120 millions of tons of coals
suffice for the requirements of our present population, we can scarcely
believe that 1,440 millions will be needed in 1950, unless we suppose
that the population of Britain will be twelve times greater than at
present; or that the population will be even greater than this, since
the consumption of coal upon our railways could scarcely be expected
to increase in proportion to the population. Now no one believes that
Britain will number 300 millions of inhabitants in 1950, or in 2950;
the country could not maintain half that number, even though all her
available stores of coal and iron, and other sources of commercial
wealth were increased a hundredfold.
It is a mistake, indeed, to extend the results of statistical research
very far beyond the time to which the facts and figures belong. It
would be easy to multiply instances of the incorrectness of such a
process. To take a single case.—When cholera has been extending its
ravages in this country, the statistics of mortality from that cause,
if studied with reference to four or five successive weeks, have
indicated a law of increase, which is very readily expressed so as
to accord with the mortality during those weeks, and perhaps two or
three following weeks. But if such a law were extended indefinitely it
might be found to imply nothing short of the complete desolation of
the country by cholera, within the space of a few months. Thus, if the
deaths (from cholera) in five successive weeks were 20, 27, 35, 47, and
63,—numbers corresponding with the general characteristics of cholera
mortality in the earlier stages of a visitation,—the weekly mortality a
year later, estimated according to the observed percentage of increase,
would be more than 173 millions! Now this method of estimation, though
leading to this preposterous conclusion as respects a more distant
epoch, would probably lead to tolerably correct results for the next
week or two after that in which 63 persons died,—the estimated numbers
being 84 and 110 for the next two weeks respectively.
It seems to me, therefore, that we are not justified, by the observed
seeming fulfilment of Mr. Jevons’s anticipations, in concluding that
a hundred years hence the consumption of coals will be 2,000 millions
of tons, or that the total consumption during the next 110 years will
be 100,000 millions of tons. We might almost as safely infer that
because a growing lad requires such and such an increase of food year
by year, the grown man will need a similar rate of increase, and the
septuagenarian require so many tons and hogsheads of solid and liquid
food _per diem_.
At present it does not seem possible to arrive at any definite
conclusions respecting the probable consumption of coal in years to
come. The range of observation is not sufficiently extended. It seems
clear, indeed, that the epoch is not near at hand when the present law
of increase will be modified. This is shown by the agreement of the
observed results during the past five years with the anticipations of
Mr. Jevons. It would be altogether unsafe to predict that the yearly
consumption will not rise to 150 or 200 or even 250 millions of tons
per annum, or to point to any definite stage at which the present
increasing rate of increase will be changed first into uniform (or
arithmetical) increase, and thence into a decreasing rate of increase.
But it appears to me that no question can exist that these changes
_will_ take place. We might even go farther, and regard it as all but
certain that the time will come when there will be no annual increase.
Nay, unless the history of this country is to differ from the history
of all other nations which have attained to great power, the time
might be expected to arrive when there will be, year by year, a slow
diminution in the commercial activity of Britain, and a corresponding
diminution in the exhaustion of her coal stores. There is room for
an amazing increase in Britain’s power and greatness, room also for
an unprecedented continuance of these attributes, while yet the coal
stores of the country remain well supplied.
Let us conceive, for instance, that the greatest annual consumption
of coal during the future years of England’s existence as a great
nation, should be set at three times her present annual consumption,
or at 350 millions of tons. Few will regard this as an unduly low
estimate when they remember that it is exceedingly unlikely that the
present population of Britain will ever be tripled, and that a triple
population could be commercially far more active (in relation to its
numbers) than the present population, with no greater consumption of
coal per head. Now, to begin with, if this enormous annual consumption
began immediately, we should yet (with Mr. Jevons’s assumption as to
the quantity of available coal) have 570 years’ lease of power instead
of 110. But, as a matter of fact, so soon as we have recognised the
principle that there is a limit to the increase of annual consumption,
we are compelled to believe that that limit will be approached by
a much gentler gradient, so to speak, than the same consumption as
attained on Mr. Jevons’s assumption. According to his view, in fact, an
annual consumption of 350 millions of tons per annum will be attained
early in the twentieth century; but according to the theory which
sets such a consumption as the highest ever to be attained, we should
place its attainment several hundreds of years later. This is a vague
statement, I admit, but the very fact on which I am mainly insisting
is this, that the evidence at present in our hands is insufficient as
a basis of exact calculation. Now, if we set 500 years hence as the
time when the annual consumption of coal will have reached the above
enormous amount, we should set the total consumption during those
centuries at about one-half that due to an annual consumption of 350
millions of tons. In that case there would still remain coal enough to
supply the country for 320 years at the same tremendous rate. In all,
on these suppositions, 820 years would be provided for. These would
be years of commercial activity far exceeding that of our own day—in
fact, they would be years during which Britain would be accumulating
wealth at a rate so enormous that at the end of the era she would be
not wholly unprovided with the means of supporting her existence as a
nation, apart from all reference to her mineral stores. It is, indeed,
utterly inconceivable, I think, that Great Britain and her people will
ever be _able_ to progress at the rate implied by these suggestions.
To conceive of Great Britain as arriving at ruin within a thousand
years by the over-rapid exhaustion of her coal stores, is, in fact,
equivalent to supposing that she will attain in the interval to a
wholly unprecedented—I had almost said a wholly incredible—degree of
wealth and power.
As regards the evidence which has been adduced respecting the extent
of the available coal supply, it is to be remarked that, on the whole,
the result cannot be regarded as unfavourable. The more sanguine
views entertained five or six years ago have not, indeed,, been fully
justified. Yet our coal supply has been shown to be enormous, even when
considered with reference to the continually increasing exhaustion.
But it must be admitted that the question of the depth to which
our coal mines may be conveniently or even possibly worked, has an
unpleasantly doubtful aspect. Of the stores which the Commissioners
regard as available a vast proportion must be mined out from depths
far exceeding any which have been at present reached in England. It is
not as yet clear how far the increase of depth will add to the cost
and risk of working; nor do I propose to discuss a subject which can
only be adequately dealt with by those who possess practical knowledge
of the details of colliery-working. I will content myself by quoting
some remarks on the subject, in an inaugural address delivered by Mr.
George Elliot (one of the Royal Commissioners) before the North of
England Institute of Mining Engineers in 1868. ‘The great depth,’ he
remarked, ‘at which many of our pits are worked, and the vast extent
of their lateral ramifications, make it more than ever necessary
that we should secure the best mode of rendering the supply of pure
air certain, regular, and safe. It is maintained that ventilating
by machinery ensures these desiderata; that the nicety with which
mechanical appliances may be regulated, the delicate adjustment of
power of which they are capable, and the complete safety with which
they may be worked, place them far before the system they are intended
to supersede. The extent of our coal supply will be materially
increased by the improvement of which this is a type.... It is probable
that the ordinary means of ventilation—whether by furnace or fan—may
be aided by a change in the force or agency employed for the purposes
of haulage and other independent work. As an instance of my meaning, I
may mention that the apparatus which I have introduced in South Wales,
and which, by means of compressed air used as a motive power instead of
steam, draws trams and pumps water with complete success, is found to
generate ice in an atmosphere which is naturally hot and oppressive.
The mechanical usefulness of these new air-engines seems capable
of indefinite extension; while, as their cooling properties form a
collateral advantage arising out of their use, it is at least possible
that they may prove valuable auxiliaries to the more regular means of
ventilation in extending the security and promoting the healthfulness
of our mines. _The difficulties of ventilation once surmounted, the
extent of coal at our disposal is incalculably increased._‘