Estimating the actual consumption of coal for home use in Great Britain
at 110 millions of tons per annum, a rise of eight shillings per ton to
consumers is equivalent to a tax of 44 millions per annum. These are
the figures taken by Sir William Armstrong in his address at Newcastle
last February. As the recent abnormal rise in the value of coal has
amounted to more than this, consumers have been paying at some periods
above a million per week as premium on fuel, even after making fair
deduction for the rise of price necessarily due to the diminishing
value of gold.
Are we, the consumers of coal, to write off all this as a dead loss,
or have we gained any immediate or prospective advantage that may be
deducted from the bad side of the account? I suspect that we shall gain
sufficient to ultimately balance the loss, and, even after that, to
leave something on the profit side.
The abundance of our fuel has engendered a shameful wastefulness that
is curiously blind and inconsistent. As a typical example of this
inconsistency, I may mention a characteristic incident. A party of
young people were sitting at supper in the house of a colliery manager.
Among them was the vicar of the parish, a very jovial and genial man,
but most earnest withal in his vocation. Jokes and banterings were
freely flung across the table, and no one enjoyed the fun more heartily
than the vicar; but presently one unwary youth threw a fragment of
bread-crust at his opposite neighbor, and thus provoked retaliation.
The countenance of the vicar suddenly changed, and in stern clerical
tones he rebuked the wickedness of thus wasting the bounties of the
Almighty. A general silence followed, and a general sense of guilt
prevailed among the revellers. At the same time, and in the same room,
a blazing fire, in an ill-constructed open fire-place, was glaring
reproachfully at all the guests, but no one heeded the immeasurably
greater and utterly irreparable waste that was there proceeding. To
every unit of heat that was fully utilized in warming the room, there
were eight or nine passing up the chimney to waste their energies upon
the senseless clouds and boundless outer atmosphere. A large proportion
of the vicar’s parishioners are colliers, in whose cottages huge fires
blaze most wastefully all day, and are left to burn all night to save
the trouble of re-lighting. The vicar diligently visits these cottages,
and freely admonishes where he deems it necessary; yet he sees in this
general waste of coal no corresponding sinfulness to that of wasting
bread. Why is he so blind in one direction, while his moral vision
is so microscopic in the other? Why are nearly all Englishmen and
Englishwomen as inconsistent as the vicar in this respect?
There are doubtless several combining reasons for this, but I
suspect that the principal one is the profound impression which we
have inherited from the experience and traditions of the horrors of
bread-famine. A score of proverbs express the important practical
truth that we rarely appreciate any of our customary blessings until
we have tasted the misery of losing them. Englishmen have tasted the
consequences of approximate exhaustion of the national grain store, but
have never been near to the exhaustion of the national supply of coal.
I therefore maintain most seriously that we need a severe coal famine,
and if all the colliers of the United Kingdom were to combine for a
simultaneous winter strike of about three or six months’ duration,
they might justly be regarded as unconscious patriotic martyrs, like
soldiers slain upon a battle-field. The evils of such a thorough famine
would be very sharp, and proportionally beneficent, but only temporary;
there would not be time enough for manufacturing rivals to sink pits,
and at once erect competing iron-works; but the whole world would
partake of our calamity, and the attention of all mankind would be
aroused to the sinfulness of wasting coal. Six months of compulsory
wood and peat fuel, with total stoppage of iron supplies, would
convince the people of these islands that waste of coal is even more
sinful than waste of bread,—would lead us to reflect on the fact that
our stock of coal is a definite and limited quantity that was placed in
the present storehouse long before human beings came upon the earth;
that every ton of coal that is wasted is lost for ever, and cannot
be replaced by any human effort, while bread is a product of human
industry, and _its_ waste may be replaced by additional human labor;
that the sin of bread-wasting does admit of agricultural atonement,
while there is no form of practical repentance that can positively and
directly replace a hundredweight of wasted coal.
Nothing short of the practical and impressive lesson of bitter want is
likely to drive from our households that wretched fetish of British
adoration, the open “Englishman’s fireside.” Reason seems powerless
against the superstition of this form of fire-worship. Tell one of the
idolaters that his household god is wasteful and extravagant, that
five-sixths of the heat from his coal goes up the chimney, and he
replies, “I don’t care if it does; I can afford to pay for it. I like
to _see_ the fire, and have the right to waste what is my own.” Tell
him that healthful ventilation is impossible while the lower part of
a room opens widely into a heated shaft, that forces currents of cold
air through doors and window leakages, which unite to form a perpetual
chilbrain stratum on the floor, and leaves all above the mantel-piece
comparatively stagnant. Tell him that no such things as “draughts”
should exist in a properly warmed and ventilated house, and that even
with a thermometer at zero outside, every part of a well-ordered
apartment should be equally habitable, instead of merely a semicircle
about the hearth of the fire-worshiper; he shuts his ears, locks up his
understanding, because his grandfather and grandmother believed that
the open-mouthed chimney was the one and only true English means of
ventilation.
But suppose we were to say, “You love a cheerful blaze, can afford to
pay for it, and therefore care not how much coal you waste in obtaining
it. We also love a cheerful blaze, but have a great aversion to
coal-smoke and tarry vapors; and we find that we can make a beautiful
fire, quite inoffensive even in the middle of the room, provided
we feed it with stale quartern loaves. We know that such fuel is
expensive, but can afford to pay for it, and choose to do so.” Would he
not be shocked at the sight of the blazing loaves, if this extravagance
were carried out?
This popular inconsistency of disregarding the waste of a valuable and
necessary commodity, of which the supply is limited and unrenewable,
while we have such proper horror of wilfully wasting another similar
commodity which can be annually replaced as long as man remains in
living contact with the earth, will gradually pass away when rational
attention is directed to the subject. If the recent very mild
suggestion of a coal-famine does something towards placing coal on a
similar pedestal of popular veneration to that which is held by the
“staff of life,” the million a week that it has cost the coal consumer
will have been profitably invested.
Many who were formerly deaf to the exhortations of fuel economists are
now beginning to listen. “_Forty shillings per ton_” has acted like an
incantation upon the spirit of Count Rumford. After an oblivion of more
than eighty years, his practical lessons have again sprung up among us.
Some are already inquiring how he managed to roast 112 lbs. of beef at
the Foundling Hospital with 22 lbs. of coal, and to use the residual
heat for cooking the potatoes, and why it is that with all our boasted
progress we do not now in the latter third of the nineteenth century,
repeat that which he did in the eighteenth.
The fact that the consumption of coal in London during the first four
months of 1873 has, in spite of increasing population, amounted to
49,707 tons less than the corresponding period of 1872, shows that some
feeble attempts have been made to economize the domestic consumption of
fuel. One very useful result of the recent scarcity of coal has been
the awakening of a considerable amount of general interest in the
work of stock-taking, a tedious process which improvident people are
too apt to shirk, but which is quite indispensable to sound business
proceedings, either of individuals or nations.
There are many discrepancies in the estimates that have been made of
the total available quantity of British coal. The speculative nature of
some of the data renders this inevitable, but all authorities appear
to agree on one point, viz., that the amount of our supplies will not
be determined by the actual total quantity of coal under our feet, but
by the possibilities of reaching it. This is doubtless correct, but
how will these possibilities be limited, and what is the extent or
range of the limit? On both these points I venture to disagree with
the eminent men who have so ably discussed this question. First, as
regards the nature of the limit or barrier that will stop our further
progress in coal-getting. This is generally stated to be the depth of
the seams. The Royal Commissioners of 1870 based their tables of the
quantity of available coal in the visible and concealed coal-fields
upon the assumption that 4000 feet is the limit of possible working.
This limit is the same that was taken by Mr. Hull ten years earlier.
Mr. Hull, in the last edition of “The Coal Fields of Great Britain,” p.
326, referring to Professor Ramsay’s estimate, says, “These estimates
are drawn up for depths down to 4000 feet below the surface, and
even beyond this limit; but with this latter quantity it is scarcely
necessary that we should concern ourselves.” I shall presently show
reasons for believing that the time may ultimately arrive when we
_shall_ concern ourselves with this deep coal, and actually get it;
while, on the other hand, that remote epoch will be preceded by another
period of practical approximate exhaustion of British coal supply,
which is likely to arrive long before we reach a working depth of 4000
feet.
The Royal Commissioners estimate that within the limits of 4000
feet we have hundreds of square miles of attainable coal capable of
yielding, after deducting 40 per cent for loss in getting, etc.,
146,480 millions of tons; or, if we take this with Mr. Hull’s deduction
of one-twentieth for seams under two feet in thickness, there remains
139,000 millions of tons, which, at present rate of consumption,
would last about 1200 years. But the rate of consumption is annually
increasing, not merely on account of increasing population, but also
from the fact that mechanical inventions are perpetually superseding
hand labor, and the source of power in such cases, is usually derived
from coal. This consideration induced Professor Jevons, in 1865, to
estimate that between 1861 and 1871 the consumption would increase from
83,500,000 tons to 118,000,000 tons. Mr. Hunt’s official return for
1871 shows that this estimate was a close approximation to the truth,
the actual total for 1871 having been 117,352,028 tons. At this rate of
an arithmetical increase of three and a half tons per annum, 139,000
millions of tons would last but 250 years. Mr. Hull, taking the actual
increase at three millions of tons per annum, extends it to 276 years.
Hitherto the annual increase has followed a geometrical, rather than
arithmetical progress, and those who anticipate a continuance of this
allow us a much shorter lease of our coal treasures. Mr. Price Williams
maintains that the increase will proceed in a diminishing ratio
like that of the increase of population; and upon this basis he has
calculated that the annual consumption will amount to 274 millions of
tons a hundred years hence, and the whole available stock of coal will
last about 360 years.
The latest returns show, for 1872, an output of 123,546,758 tons,
which, compared with 1871, gives a rate of increase of more than double
the estimate of Mr. Hull, and indicate that prices have not yet risen
sufficiently to check the geometrical rate of increase.[24] Mr Hull
very justly points out the omission in those estimates which do not
“take into account the diminishing ratio at which coal must be consumed
when it becomes scarcer and more expensive;” but, on the other hand,
he omits the opposite influence of increasing prices on production,
which has been strikingly illustrated by the extraordinary number of
new coal-mining enterprises that have been launched during the last
six months. If we continue as we are now proceeding, a practical and
permanent coal famine will be upon us within the lifetime of many of
the present generation. By such a famine, I do not mean an actual
exhaustion of our coal seams (which will never be effected), but such
a scarcity and rise of prices as shall annihilate the most voracious
of our coal-consuming industries, those which depend upon abundance of
cheap coal, such as the manufacture of pig-iron, etc.[25]
The action of increasing prices has been but lightly considered
hitherto, though its importance is paramount in determining the limits
of our coal supply; I even venture so far as to affirm that it is
not the depth of the coal seams, not the increasing temperature nor
pressure as we proceed downwards, nor even thinness of seam, that will
practically determine the limits of British coal-getting, but simply
the price per ton at the pit’s mouth.
In proof of this, I may appeal to actual practice. Mr. Hull and others
have estimated the working limit of thinness at two feet, and agree in
regarding thinner seams than this as unworkable. This is unquestionably
correct so long as the getting is effected in the usual manner. A
collier cannot lie down and hew a much thinner seam than this, if he
works as colliers work at present. But the lead and copper miners
succeed in working far thinner lodes, even down to the thickness of a
few inches, and the gold-digger crushes the hardest component of the
earth’s crust to obtain barely visible grains of the precious metal.
This extension of effort is entirely determined by market value. At
a sufficiently high price the two-feet limit of coal-getting would
vanish, and the collier would work after the manner of the lead-miner.
We may safely apply the same reasoning to the limits of depth. The 4000
feet limit of the Royal Commissioners is _at present_ unattainable,
simply because the immediately prospective price of coal would not
cover the cost of such deep sinking and working; but as prices go up,
pits will go down, deeper and deeper still.
The obstacles which are assumed to determine the 4000 feet limit
are increasing density due to greater pressure, and the elevation
of temperature which proceeds as we go downwards. The first of
these difficulties has, I suspect, been very much overstated, if
not altogether misunderstood; though it is but fair to add that Mr.
Hull, who most prominently dwells upon it, does so with all just
and philosophic caution. He says that “it is impossible to speak
with certainty of the effect of the accumulative weight of 3000 or
4000 feet of strata on mining operations. In all probability one
effect would be to increase the density of the coal itself, and
of its accompanying strata, so as to increase the difficulty of
excavating,” and he concludes by stating that “in the face of these
two obstacles—temperature and pressure, ever increasing with the
depth—I have considered it utopian to include in calculations having
reference to coal supply any quantity, however considerable, which lies
at a greater depth than 4000 feet. Beyond that depth I do not believe
that it will be found practicable to penetrate. Nature rises up, and
presents insurmountable barriers.”[26]
On one point I differ entirely from Mr. Hull, viz., the conclusion
that the increased “density of the coal itself and of its accompanying
strata” will offer any serious obstacle. On the contrary, there is good
reason to believe that such density is one of the essential conditions
for working deep coal. Even at present depths of working, density and
hardness of the accompanying strata is one of the most important aids
to easy and cheap coal-getting. With a dense roof and floor the collier
works vigorously and fearlessly, and he escapes the serious cost of
timbering.
Those who have never been underground, and only read of colliery
disasters, commonly regard the fire-damp and choke-damp as the
collier’s most deadly enemies, but the collier himself has quite as
much dread of a rotten roof as of either of these: he knows by sad
experience how much bruising, and maiming, and crushing of human limbs
are due to the friability of the rock above his head. Mr. Hull quotes
the case of the Dunkinfield colliery, where, at a depth of about 2500
feet, the pressure is “so resistless as to crush in circular arches of
brick four feet thick,” and to snap a cast-iron pillar in twain; but he
does not give any account of the density of the accompanying strata at
the place of these occurrences. I suspect that it was simply _a want of
density_ that allowed the superincumbent pressure to do such mischief.
The circular arches of brick four feet thick were but poor substitutes
for a roof of solid rock of 40 or 400 feet in thickness; an arch cut
in such a rock would be all key-stone: and I may safely venture to
affirm that if, in the deep sinkings of the future, we do encounter the
increased density which Mr. Hull anticipates, this will be altogether
advantageous. I fear, however, that it will not be so, that the chief
difficulty of deep coal-mining will arise from occasional “running
in” due to deficient density, and that this difficulty will occur in
about the same proportion of cases as at present, but will operate more
seriously at the greater depths.
A very interesting subject for investigation is hereby suggested.
Do rocks of given composition and formation increase in density as
they dip downwards; and if so, does this increase of density follow
any law by which we may determine whether their power of resisting
superincumbent pressure increases in any approach to the ratio of the
increasing pressure to which they are naturally subjected? If the
increasing density and power of resistance reaches or exceeds this
ratio, deep mining has nothing to fear from pressure. If they fall
short of it, the difficulties arising from pressure may be serious.
Friability, viscosity, and power of resisting a crushing strain must be
considered in reference to this question.
Mr. Hull has collected a considerable amount of data bearing upon
the rate of increase of temperature with depth. His conclusions give
a greater rate of increase than is generally stated by geologists;
but for the present argument I will accept, without prejudice, as the
lawyers say, his basis of a range of 1° F. for 60 feet. According
to this, the _rocks_ will reach 99.6°, a little above blood-heat,
at 3000 feet, and 116.3° at the supposed limit of 4000 feet. It is
assumed by Mr. Hull, by the Commissioners, and most other authorities,
that this rock temperature of 116° will limit the possibilities of
coal-mining. At the average prices of the last three years, or the
prospective prices of the next three years, this temperature may be,
like difficulties of the thin seams, an insurmountable barrier; but I
contend that at higher prices we may work coal at this, and even far
higher, rock temperatures; that it matters not how high the thermometer
rises as we descend, we shall still go lower and still get coal so long
as prices rise with the mercury. Given this condition, and I have no
doubt that coal may be worked where the rock temperature shall reach or
even exceed 212°. I do not say that we shall actually work coal at such
depths; but if we do not, the reason will be, not that the thermometer
is too high, but that prices are too low; in other words, value, not
temperature, will determine the working limits.
Mr. Leifchild, in the last number of the “Edinburgh Review,” in
discussing this question, tells us that “the normal heat of our blood
is 98°, and fever heat commences at 100°, and the extreme limit of
fever heat may be taken at 112°. Dr. Thudichum, a physician who has
specially investigated this subject, has concluded from experiments
on his own body at high temperatures, that at a heat of 140° no work
whatever could be carried on, and that at a temperature of from 130°
to 140° only a very small amount of labor, and that at short periods,
was practicable; and further, that human labor daily, and at ordinary
periods, is limited by 100° of temperature, as a fixed point, and then
the air must be dry, for in moist air he did not think men could endure
ordinary labor at a temperature exceeding 90°.”
It may be presumptuous on my part to dispute the conclusions of a
physician on such a subject, but I do so nevertheless, as the data
required are simple practical facts such as are better obtained by
furnace-working than by sick-room experience.
During the hottest days of the summer of 1868 I was engaged in making
some experiments in the re-heating furnaces at Sir John Brown & Co.’s
works, Sheffield, and carried a thermometer about with me which I
suspended in various places where the men were working. At the place
where I was chiefly engaged (a corner between two sets of furnaces),
the thermometer, suspended in a position where it was not affected
by direct radiations from the open furnaces, stood at 120° while the
furnace doors were shut. The _radiant_ heat to which the men themselves
were exposed while making their greatest efforts in placing and
removing the piles was far higher than this, but I cannot state it, not
having placed the thermometer in the position of the men. In one of
the Bessemer pits the thermometer reached 140°, and men worked there
at a kind of labor demanding great muscular effort. It is true that
during this same week the puddlers were compelled to leave their work;
but the tremendous amount of concentrated exertion demanded of the
puddler in front of a furnace, which, during the time of removing the
balls, radiates a degree of heat quite sufficient to roast a sirloin
of beef if placed in the position of the puddles hands, is beyond
comparison with that which would be demanded of a collier working even
at a depth giving a theoretical rock temperature of 212°, and aided
by the coal-cutting and other machinery that sufficiently high prices
would readily command. In some of the operations of glass-making, the
ordinary summer working temperature is considerably above 100°, and
the radiant neat to which the workmen are subjected far exceeds 212°.
This is the case during a “pot setting,” and in the ordinary work of
flashing crown glass.
As regards the mere endurance of a high temperature, the well-known
experiments of Blagden, Sir Joseph Banks, and others have shown that
the human body can endure for short periods a temperature of 260°
F., and upwards. My own experience of furnace-work, and of Turkish
baths, quite satisfies me that I could do a fair day’s work of six
or eight hours in a temperature of 130° F., provided I were free from
the encumbrances of clothing, and had access to abundance of tepid
water. This in a still atmosphere; but with a moving current of dry
air capable of promoting vigorous evaporation from the skin, I suspect
that the temperature might be ten or fifteen degrees higher. I _enjoy_
ordinary walking exercise in a well-ventilated Turkish bath at 150°,
and can endure it at 180°.
In order to obtain further information on this point, I have written to
Mr. Tyndall, the proprietor of the Turkish baths at Newington Butts. He
is an architect, who has had considerable experience in the employment
of workmen and in the construction of Turkish baths and other hot-air
chambers. He says: “Shampooers work in my establishment from four to
five hours at a time _in a moist atmosphere_ at a temperature ranging
from 105° to 110°. I have myself worked twenty hours out of twenty-four
in one day in a temperature over 110°. Once for one half-hour I
shampooed in 185°. At the enamel works in Pimlico, belonging to Mr.
Mackenzie, men work daily in a heat of over 300°. The moment a man
working in a 110° heat begins to drink alcohol, his tongue gets
parched, and he is obliged to continue drinking while at work, and the
brain gets so excited that he cannot do half the amount. I painted my
skylights, taking me about four hours, at a temperature of about 145°;
also the hottest room skylights, which took me one hour, coming out
at intervals for “a cooler,” at a temperature of 180°. I may add in
conclusion, that a man can work well in a moist temperature of 110° if
he perspires freely.”
The following, by a writer whose testimony may be safely accepted, is
extracted from an account of ordinary passenger ships of the Red Sea,
in the “Illustrated News,” of November 9, 1872: “The temperature in
the stoke-hole was 145°. The floor of this warm region is close to
the ship’s keel, so it is very far below. There are twelve boilers,
six on each side, each with a blazing furnace, which has to be opened
at regular intervals to put in new coals, or to be poked up with long
iron rods. This is the duty of the poor wretches who are doomed to
this work. It is hard to believe that human beings could be got to
labor under such conditions, yet such persons are to be found. The work
of stoking or feeding the fires is usually done by Arabs, while the
work of bringing the coal from the bunkers is done by sidi-wallahs or
negroes. At times some of the more intelligent of these _are promoted
to the stoking_. The negroes who do this kind of work come from
Zanzibar. They are generally short men, with strong limbs, round bullet
heads, and the very best of good nature in their dispositions. Some of
them will work half an hour in such a place as the stoke-hole without
a drop of perspiration on their dark skins. Others, particularly the
Arabs, when it is so hot as it often is in the Red Sea, have to be
carried up in a fainting condition, and are restored to animation by
dashing buckets of water over them as they lie on deck.”
It must be remembered that the theoretical temperature of 116° at
4000 feet, the 133° at 5000 feet, or the 150° at 6000 feet, are
the temperatures of _the undisturbed rock_; that this rock is a
bad conductor of heat, whose surface may be considerably cooled by
radiation and convection; and therefore we are by no means to regard
the rock temperature as that of the air of the roads and workings
of the deep coal-pits of the future.[27] It is true that the Royal
Commissioners have collected many facts showing that the actual
difference between the face of the rocks of certain pits and the air
passing through them is but small; but these data are not directly
applicable to the question under consideration for the three following
reasons:
_First._ The comparisons are made between the temperature of the
air and the actual temperature of the opened and already cooled
strata, while the question to be solved is the difference between the
theoretical temperature of the unopened earth depths and that of the
air in roads and working’s to be opened through them.
_Second._ The cooling effect of ventilation must (as the Commissioners
themselves state) increase in a ratio which “somewhat exceeds the ratio
of the difference between the temperature of the air and that of the
surrounding surface with which it is in contact.” Thus, the lower we
proceed the more and more effectively cooling must a given amount of
ventilation become.
The third, and by far the most important, reason is, that in the deep
mining of the future, special means will be devised and applied to
the purpose of lowering the temperature of the workings; that as the
descending efforts of the collier increase with the ascending value of
the coal, a new problem will be offered for solution, and the method of
working coal will be altered accordingly. In the cases quoted by the
Commissioners, the few degrees of cooling were effected by a system of
ventilation that was devised to meet the requirements of respiration,
and not for the purpose of cooling the mine.
It would be very presumptuous for anyone in 1873 to say how this
special cooling will actually be effected, but I will nevertheless
venture to indicate one or two principles which may be applied to the
solution of the problem. First of all, it must be noted that very deep
mines are usually dry; and there is good reason to believe that, before
reaching the Commissioners’ limit of 4000 feet, dry mining would be the
common, and at and below 4000 feet the universal, case. At present we
usually obtain coal from water-bearing strata, and all our arrangements
are governed by this very serious contingency. With water removed, the
whole system of coal-mining may be revolutionized, and thus the aspect
of this problem of cooling the workings would become totally changed.
Those who are acquainted with the present practice of mining are aware
that when an estate is taken, and about to be worked for coal, the
first question to be decided is the dip of the measures, in order that
the sinking may be made “on the deep” of the whole range. The pits are
not sunk at that part of the same range where, at first sight, the coal
appears the most accessible, but, on the contrary, at the deepest part.
It is then carried on to some depth below the coal seam which is to be
worked, in order to form a “sumpf” or receptacle from which the water
may be wound or pumped. The necessity for this in water-bearing strata
is obvious enough. If the collier began at the shallowest portion of
his range, and attempted to proceed downwards, he would be “drowned
out” unless he worked as a coal-diver rather than a coal-miner. By
sinking in the deep he works upwards, away from the water, which all
drains down to the sumpf, from which it is pumped.
The modern practice is to sink “a pair of pits,” _both on the deep_,
and within a short distance of each other. The object of the second is
ventilation. By contrivances, which I need not here detail, the air is
made to descend one of the pits, “the downcast shaft,” then to traverse
the roads and workings wherein ventilation is required, and return by a
reverse route to the “upcast shaft,” by which it ascends to the surface.
Thus it will be seen that, whenever the temperature of the roads and
workings exceeds that of the outer atmosphere; the air currents have to
be forced to travel through the mine in a direction contrary to their
natural course. The cooler air of the downcast shaft has to climb the
inclined roads, and then after attaining its maximum temperature in
the fresh workings must _descend_ the roads till it reaches the upcast
shaft. The cool air must rise and the warmer air descend.
What, then, would be the course of the mining engineer when all
the existing difficulties presented by water-bearing strata should
be removed, and their place taken by a new and totally different
obstacle, viz., high temperature? Obviously to reverse the present
mode of working—to sink on the upper part of the range and drive
downwards. In such a system of working the ventilation of the pit will
be most powerfully aided or altogether effected by natural atmospheric
currents. An upcast once determined by artificial means, it will
thereafter proceed spontaneously, as the cold air of the downcast
shaft will travel by a descending road to the workings, and then after
becoming heated will simply obey the superior pressure of the heavy
column behind, and proceed by an upward road to the upcast shaft. As
the impelling force of the air current will be the difference between
the weight of the cool column of air in the downcast shaft and roads
and the warm column in the upcast, the available force of natural
ventilation and cooling will increase just as demanded, _i.e._, it
will increase with the depth of the workings and the heat of the
rocks. A mining engineer who knows what is actually done with present
arrangements, will see at once that with the above-stated advantages
a gale of wind or even a hurricane might be directed through any
particular roads or long-wall workings that were once opened. Let us
suppose the depth to be 5000 feet, the rock temperature at starting
133°, and that of the outer air 60°, we should have a torrent of air,
73° cooler than the rocks, rushing furiously downwards, then past the
face of the heated strata, and absorbing its heat to such an extent
that the upcast shaft would pour forth a perpetual blast of hot air
like a gigantic furnace chimney.
But this is not all; the heat and dryness of these deep workings of the
future place at our disposal another and still more efficient cooling
agency than even that of a hurricane of dry-air ventilation. In the
first part of the sinking of the deep shafts the usual water-bearing
strata would be encountered, and the ordinary means of “tubbing” or
“coffering” would probably be adopted for temporary convenience during
sinking. Doorways, however, would be left in the tubbing at suitable
places for tapping at pleasure the wettest and most porous of the
strata. Streams of cold water could thus be poured down the sides of
the shaft, which, on reaching the bottom, would flow by a downhill road
into the workings. The stream of air rushing by the same route and
becoming heated in its course would powerfully assist the evaporation
of the water. The deeper and hotter the pit, the more powerful would be
these cooling agencies.
As the specific heat of water is about five times that of the
coal-measure rocks, or the coal itself, every degree of heat
communicated to each pound of water would abstract one degree from five
pounds of rocks. But in the conversion of water at 60° into vapor at
say 100°, the amount of heat absorbed is equivalent to that required
to raise the same weight of water about 1000°, and thus the effective
cooling power on the rock would be equivalent to 5000°.
The workings once opened (I assume as a matter of course that by this
time pillar-and-stall working will be entirely abandoned for long-wall
or something better), there would be no difficulty in thus pouring
streams of water and torrents of air through the workings during the
night, or at any suitable time preparatory to the operations of the
miner, who long before the era of such deep workings will be merely the
director of coal-cutting and loading machinery.
Given a sufficiently high price for coal at the pit’s mouth to pay
wages and supply the necessary fixed capital, I see no insuperable
difficulty, _so far as mere temperature is concerned_, in working coal
at double the depth of the Royal Commissioners’ limit of possibility.
At such a depth of 8000 feet the theoretical rock-temperature is 183°.
By the means above indicated, I have no doubt that this could be
reduced to an _air_ temperature below 110°—that at which Mr.
Tyndall’s shampooers ordinarily work. Of course the newly-exposed
face of the coal would have its initial temperature of 183°; but this
is a trivial heat compared to the red-hot radiant surfaces to which
puddlers, shinglers, glassmakers, etc., are commonly exposed. Divested
of the incumbrance of clothing, with the whole surface of the skin
continuously fanned by a powerful stream of air—which, during working
hours need be but partly saturated with vapor—a sturdy midland or
north-countryman would work merrily enough at short hours and high
wages, even though the newly-exposed face of coal reached 212°; for
we must remember that this new coal-face would only correspond to
the incomparably hotter furnace-doors and fires of the steamship
stoke-holes.
The high temperature at 8000 or even 10,000 feet would present a really
serious difficulty during the first opening of communications between
the two pits. A spurt of brave effort would here be necessary, and if
anybody doubts whether Englishmen could be found to make the effort,
let him witness a “pot-setting” at a glass-house. Negro labor might be
obtained if required, but my experience among English workmen leads me
to believe that they will never allow negroes or any others to beat
them at home in any kind of work where the wages paid are proportionate
to the effort demanded.
If I am right in the above estimates of working possibilities, our coal
resources may be increased by about forty thousand millions of tons
beyond the estimate of the Commissioners. To obtain such an additional
quantity will certainly be worth an effort, and unless we suffer a far
worse calamity than the loss of all our minerals, viz., a deterioration
of British energy, the effort will assuredly be made.
I have said repeatedly that it is not physical difficulties but market
value that will determine the limits of our coal-mining. This, like
all other values, is of course determined by the relation between
demand and supply. Fuel being one of the absolute necessaries of life,
the demand for it must continue so long as the conditions of human
existence remain as at present, and the outer limits of the possible
value of coal will be determined by that of the next cheapest kind of
fuel which is capable of superseding it.
We begin by working the best and most accessible seams, and while those
remain in abundance the average value of coal will be determined by the
cost of producing it under these easy conditions. Directly these most
accessible seams cease to supply the whole demand, the market value
rises until it becomes sufficient to cover the cost of working the less
accessible; and the average value will be regulated not by the cost of
working what remains of the first or easy mines, but by that of working
the most difficult that must be worked in order to meet the demand.
This is a simple case falling under the well-established economic law,
that the natural or cost value of any commodity is determined by the
cost value of the most costly portion of it. Thus, the only condition
under which we can proceed to sink deeper and deeper, is a demand of
sufficient energy to keep pace with the continually increasing cost
of production. This condition can only be fulfilled when there is no
competing source of cheaper production which is adequate to supply the
demand.
The question then resolves itself into this: Is any source of supply
likely to intervene that will prevent the value of coal from rising
sufficiently to cover the cost of working the coal seams of 4000 feet
and greater depth? Without entering upon the question of peat and
wood fuel, both of which will for some uses undoubtedly come into
competition with British coal as it rises in value, I believe that
there are sound reasons for concluding that our London fireplaces,
and those of other towns situated on the sea-coast and the banks of
navigable rivers, will be supplied with transatlantic coal long before
we reach the Commissioner’s limit of 4000 feet. The highest prices of
last winter, if steadily maintained, would be sufficient to bring about
this important change. Temporary upward jerks of the price of coal have
very little immediate effect upon supply, as the surveying, conveyance,
boring, sinking, and fully opening of a new coal estate is a work of
some years.
The Royal Commissioners estimate that the North-American coal-fields
contain an untouched coal area equal to seventy times the whole of
ours. Further investigation is likely to increase rather than diminish
this estimate. An important portion of this vast source of supply is
well situated for shipment, and may be easily worked at little cost.
Hitherto, the American coal-fields have been greatly neglected, partly
on account of the temptations to agricultural occupation which are
afforded by the vast area of the American continent, and partly by
the barbarous barriers of American politics. Large amounts of capital
which, under the social operation of the laws of natural selection,
would have been devoted to the unfolding of the vast mineral resources
of the United States, are still wastefully invested in the maintenance
of protectively nursed and sickly imitation of English manufactures.
When the political civilization of the United States become
sufficiently advanced to establish a national free-trade policy, this
perverted capital will flow into its natural channels, and the citizens
of the States will be supplied with the more highly elaborated
industrial products at a cheaper rate than at present, by obtaining
them in exchange for their superabundant raw material from those
European countries where population is overflowing the raw material
supplies.
When this time arrives, and it may come with the characteristic
suddenness of American changes, the question of American _versus_
English coal in the English markets will reduce itself to one of
horizontal _versus_ vertical difficulties. If at some future period the
average depth of the Newcastle coal-pits becomes 3000 feet greater than
those of the pits near the coast of the Atlantic or American lakes, and
if the horizontal difficulties of 3000 miles of distance are less than
the vertical difficulties of 3000 feet of depth, then coals will be
carried from America to Newcastle. They will reach London and the towns
on the South Coast before this, that is, when the vertical difficulties
at Newcastle plus those of horizontal traction from Newcastle to the
south, exceed those of eastward traction across the Atlantic.
As the cost of carriage increases in a far smaller ratio than the
open ocean distance, there is good reason for concluding that the
day when London houses will be warmed by American coal is not very
far distant. We, in England, who have outgrown the pernicious folly
of “protecting native industry” will heartily welcome so desirable a
consummation. It will render unnecessary any further inquiry into the
existence of London “coal rings” or combinations for restricted output
among colliers or their employers. If any morbid impediments to the
free action of the coal trade do exist, the stimulating and purgative
influence of foreign competition will rapidly restore the trade to a
healthy condition.
The effect of such introduction of American coal will not be to
perpetually lock up our deep coal nor even to stop our gradual progress
towards it. We shall merely proceed downwards at a much slower rate,
for in America, as with ourselves, the easily accessible coal will be
first worked, and as that becomes exhausted, the deeper, more remote,
thinner, and inferior will only remain to be worked at continually
increasing cost. When both our own and foreign coal cost more than
peat, or wood, or other fuel, then and therefore will coal become quite
inaccessible to us, and this will probably be the case long before
we are stopped by the physical obstacles of depth, density, or high
temperature.
As this rise of value must of necessity be gradual, and as the
superseding of British by foreign coal, as well as the final disuse
of coal, will gradually converge from the circumference towards the
centres of supply, from places distant from coal-pits to those close
around them, we shall have ample warning and opportunity for preparing
for the social changes that the loss of the raw material will enforce.
The above-quoted writer, in the “Edinburgh Review,” expresses in
strong and unqualified terms an idea that is very prevalent in England
and abroad: he says that, “The course of manufacturing supremacy of
wealth and of power is directed by coal. That wonderful mineral, of
the possession of which Englishmen have thought so little but wasted
so much, is the modern realization of the philosopher’s stone. This
chemical result of primeval vegetation has been the means by its
abundance of raising this country to an unprecedented height of
prosperity, and its deficiency might have the effect of lowering it to
slow decline.”
*** “It raises up one people and casts down another; it makes railways
on land and paths on the sea. It founds cities, it rules nations, it
changes the course of empires.”
The fallacy of these customary attributions of social potency to mere
mineral matter is amply shown by facts that are previously stated by
the reviewer himself. He tells us that “the coal-fields of China extend
over an area of 400,000 square miles; and a good geologist, Baron Von
Richthofen, has reported that he himself has found a coal-field in
the province of Hunau covering an area of 21,700 square miles, which
is nearly double our British coal area of 12,000 square miles. In the
province of Shansi, the Baron discovered nearly 30,000 square miles
of coal with unrivaled facilities for mining. But all these vast
coal-fields, capable of supplying the whole world for some thousands of
years to come, are lying unworked.”
If “the course of manufacturing supremacy of wealth and of power” were
directed by coal, then China, which possesses 33·3 times more of this
directive force than Great Britain, and had so early a start in life,
should be the supreme summit of the industrial world. If this solid
hydrocarbon “raises up one people and casts down another,” the Chinaman
should, be raised thirty-three times and three tenths higher than the
Englishman; if it “makes railways on land and paths on the sea,” the
Chinese railways should be 33·3 times longer than ours, and the tonnage
of their mercantile marine 33·3 times greater.
Every addition to our knowledge of the mineral resources of other parts
of the world carries us nearer and nearer to the conclusion that the
old idea of the superlative abundance of the natural mineral resources
of England is a delusion. We are gradually discovering that, with the
one exception of tin-stone, we have but little if any more than an
average supply of useful ores and mineral fuel. It is a curious fact,
and one upon which we may profitably ponder, that the poorest and the
worst iron ores that have ever been commercially reduced, are those of
South Staffordshire and the Cleveland district, and these are the two
greatest iron-making centres of the world. There are no ores of copper,
zinc, tin, nickel, or silver in the neighborhood of Birmingham, nor any
golden sands upon the banks of the Rea, yet this town is the hardware
metropolis of the world, the fatherland of gilding and plating, and is
rapidly becoming supreme in the highest art of gold and silver work.
These, and a multitude of other analogous facts, abundantly refute the
idea that the native minerals, the natural fertility, the navigable
rivers, or the convenient seaports, determine the industrial and
commercial supremacy of nations. The moral forces exerted by the
individual human molecules are the true components which determine
the resulting force and direction of national progress. It is the
industry and skill of our workmen, the self-denial, the enterprise,
and organizing ability of our capitalists, that has brought our coal
so precociously to the surface and redirected for human advantage the
buried energies of ancient sunbeams, while the fossil fuel of other
lands has remained inert.
The foreigner who would see a sample of the source of British
prosperity must not seek for it in a geological museum or among our
subterranean rocks; let him rather stand on the Surrey side of London
Bridge from 8 to 10 A.M. and contemplate the march of one of the
battalions of our metropolitan industrial army, as it pours forth in
an unceasing stream from the railway stations towards the City. An
analysis of the moral forces which produce the earnest faces and rapid
steps of these rank and file and officers of commerce will reveal
the true elements of British greatness, rather than any laboratory
dissection of our coal or ironstone.
Fuel and steam-power have been urgently required by all mankind.
Englishmen supplied these wants. Their urgency was primary and they
were first supplied, even though the bowels of the earth had to be
penetrated in order to obtain them. In the present exceptional and
precocious degree of exhaustion of our coal treasures, we have the
_effect_ not the _cause_ of British industrial success.
If in a ruder age our greater industrial energy enabled us to take
the lead in supplying the ruder demands of our fellow-creatures, why
should not a higher culture of those same abundant energies qualify us
to maintain our position and enable us to minister to the more refined
and elaborate wants of a higher civilization? There are other necessary
occupations quite as desirable as coal-digging, furnace-feeding, and
cotton-spinning.
The approaching exhaustion of our coal supplies should therefore serve
us as a warning for preparation. Britain will be forced to retire from
the coal trade, and should accordingly prepare her sons for higher
branches of business,—for those in which scientific knowledge and
artistic training will replace mere muscular strength and mechanical
skill. We have attained our present material prosperity mainly by our
excellence in the use of steam-power; let us now struggle for supremacy
in the practical application of brain-power.
We have time and opportunity for this. The exhaustion of our coal
supplies will go on at a continually retarding pace—we shall always
be approaching the end, but shall never absolutely reach it, as every
step of approximation will diminish the rate of approach; like the
everlasting process of reaching a given point by continually halving
our distance from it.
First of all we shall cease to export coal; then we shall throw up
the most voracious of our coal-consuming industries, such as the
reduction of iron-ore in the blast-furnace; then copper-smelting and
the manufacture of malleable iron and steel from the pig, and so on
progressively. If we keep in view the natural course and order of
such progress, and intelligently prepare for it, the loss of our coal
need not in the smallest degree retard the progress of our national
prosperity.
If, however, we act upon the belief that the advancement of a nation
depends upon the mere accident of physical advantages, if we fold our
arms and wait for Providence to supply us with a physical substitute
for coal, we shall become Chinamen, minus the unworked coal of China.
If our educational efforts are conducted after the Chinese model; if we
stultify the vigor and freshness of young brains by the weary, dull,
and useless cramming of words and phrases; if we poison and pervert
the growing intellect of British youth by feeding it upon the decayed
carcases of dead languages, and on effete and musty literature, our
progress will be proportionately Chinaward; but if we shake off that
monkish inheritance which leads so many of us blindly to believe that
the business of education is to produce scholars rather than men, and
direct our educational efforts towards the requirements of the future
rather than by the traditions of the past, we need have no fear that
Great Britain will decline with the exhaustion of her coal-fields.
The teaching and training in schools and colleges must be directly and
designedly preparatory to those of the workshop, the warehouse, and the
office; for if our progress is to be worthy of our beginning, the moral
and intellectual dignity of industry must be formally acknowledged
and systematically sustained and advanced. Hitherto, we have been the
first and the foremost in utilizing the fossil forces which the miner
has unearthed; hereafter we must in like manner avail ourselves of
the living forces the philosopher has revealed. Science must become
as familiar among all classes of Englishmen as their household fuel.
The youth of England must be trained to observe, generalize, and
_investigate_ the phenomena and forces of the world outside themselves;
and also those moral forces within themselves, upon the right or wrong
government of which the success or failure, the happiness or misery of
their lives will depend.
With such teaching and training the future generations of England will
make the best and most economical use of their coal while it lasts, and
will still advance in material and moral prosperity in spite of its
progressive exhaustion.
“THE ENGLISHMAN’S FIRESIDE.”
During the investment of Paris, the _Comptes Rendus_ of the Acadamy
of Sciences were mainly filled with papers on the construction and
guidance of balloons; with the results of ingenious researches on
methods of making milk and butter without the aid of cows; on the
extraction of nutritious food from old boots, saddles, and other
organic refuse; and other devices for rendering the general famine more
endurable. In like manner, our present coal famine is directing an
important amount of scientific, as well as commercial, attention to the
subject of economizing coal and finding substitutes for it.
A few thoughtful men have shocked their fellow-sufferers very
outrageously by wishing that coal may reach 3_l._ per ton, and remain
at that price for a year or two. I confess that, in spite of my own
empty coal-cellar and small income, I am one of those hard-hearted cool
calculators, being confident that, even from the narrow point of view
of my own outlay in fuel, the additional amount I should thus pay in
the meantime would be a good investment, affording by an ample return
in the saving due to consequent future cheapness.
Regarded from a national point of view, I am convinced that 3_l._ a
ton in London, and corresponding prices in other districts, if thus
maintained, would be an immense national blessing. I say this, being
convinced that nothing short of pecuniary pains and penalties of
ruinous severity will stir the blind prejudices of Englishmen, and
force them to desist from their present stupid and sinful waste of the
greatest mineral treasure of the island.
One of the grossest of our national manifestations of Conservative
stupidity is our senseless idolatrous worship of that domestic fetish,
“the Englishman’s fireside.” We sacrifice health, we sacrifice comfort,
we begrime our towns and all they contain with sooty foulness, we
expend an amount far exceeding the interest of the national debt,
and discount our future prospects of national prosperity, in order
that we may do what? Enjoy the favorite recreation of idiots. It is a
well-known physiological fact that an absolute idiot, with a cranium
measuring sixteen inches in circumference, will sit and stare at a
blazing fire for hours and hours continuously, all the day long, except
when feeding, and that this propensity varies with the degree of mental
vacuity.
Few sights are more melancholy than the contemplation of a party
of English fire-worshipers seated in a semicircle round the family
fetish on a keen frosty day. They huddle together, roast their knees,
and grill their faces, in order to escape the chilling blast that is
brought in from all the chinks of leaky doors and windows by the very
agent they employ, at so much cost, for the purpose of keeping the cold
away. The bigger the fire the greater the draught, the hotter their
faces the colder their backs, the greater the consumption of coal the
more abundant the crop of chilblains, rheumatism, catarrh, and other
well-deserved miseries.
The most ridiculous element of such an exhibition is the complacent
self-delusion of the victims. They believe that their idol bestows upon
them an amount of comfort unknown to other people, that it affords
the most perfect and salubrious ventilation, and, above all, that it
is a “cheerful” institution. The “cheerfulness” is, perhaps, the
broadest part of the whole caricature, especially when we consider
that, according to this theory of the cheerfulness of fire-gazing, the
16-inch idiot must be the most cheerful of all human beings.
The notion that our common fireplaces and chimneys afford an efficient
means of ventilation, is almost too absurd for serious discussion.
Everybody who has thought at all on the subject is aware that in
cold weather the exhalations of the skin and lungs, the products of
gas-burning, etc., are so much heated when given off that they rise
to the upper part of the room (especially if any cold outer air is
admitted), and should be removed from there before they cool again and
descend. Now, our fireplace openings are just where they ought _not_ to
be for ventilation; they are at the lower part of the room, and thus
their action consists in creating a current of cold air or “draught”
from doors and windows, which cold current at once descends, and then
runs along the floor, chilling our toes and provoking chilblains.
This cold fresh air having done its worst in the way of making us
uncomfortable, passes directly up the chimney without doing us any
service for purposes of respiration. Our mouths are usually above the
level of the chimney opening, and thus we only breathe the vitiated
atmosphere which it fails to remove.
Not only does the fire-opening fail to purify the air we breathe, it
actually prevents the leakage of the lower part of the windows and
doors from assisting in the removal of the upper stratum of vitiated
air, for the strong up-draught of the chimney causes these openings
to be fully occupied by an inflowing current of cold air, which at
once descends, and then proceeds, as before stated, to the chimney.
If the leakage is insufficient to supply the necessary amount of
chilblain-making and bronchitis-producing draught, it has to enter
by way of the chimney-pot in the form of occasional spasms of
down-draught, accompanied by gusts of choking and blackening smoke. It
is a fact not generally known, that smoky chimneys are especial English
institutions, one of the peculiar manifestations of our very superior
domestic comfortableness.
It is true that, in some of our rooms, an Arnott’s ventilator opens
into the upper part of the chimney, but this was intended by Dr.
Arnott as an adjunct to his modification of the German stove, and such
ventilator can only act efficiently where a stove is used. The pressure
required to fairly open it can only be regularly obtained when the
chimney is closed below, or its lower opening is limited to that of a
stovepipe.
The mention of a German stove has upon an English fire-worshiper a
similar effect to the sight of water upon a mad dog. Again and again,
when I have spoken of the necessity of reforming our fireplaces, the
first reply elicited has been, “What, would you have us use German
stoves?” In every case where I have inquired of the exclaimer, “What
sort of a thing is a German stove?” the answer has proved that the
exclamation was but a manifestation of blind prejudice based upon
total ignorance. These people who are so much shocked at the notion
of introducing “German stoves” have no idea of the construction
of the stoves which deservedly bear this title. Their notion of a
German stove is one of those wretched iron boxes of purely English
invention known to ironmongers as “shop stoves.” These things get red
hot, their red-hot surface frizzles the dust particles that float in
the atmosphere and perfume the apartment accordingly. This, however
disagreeable, is not very mischievous, perhaps the reverse, as many of
these dust particles, which are revealed by a sunbeam, are composed
of organic matter which, as Dr. Tyndall argues, may be carriers of
infection. If we must inhale such things, it is better that we should
breathe them cooked than take them raw.
The true cause of the headaches and other mischief which such stoves
unquestionably induce is very little understood in this country. It
has been falsely attributed to over-drying of the atmosphere, and
accordingly evaporating pans and other contrivances have been attached
to such stoves, but with little or no advantage. Other explanations
are given, but the true one is that iron _when red hot is permeable by
carbonic oxide_. This was proved by the researches of Professor Graham,
who showed that this gas not only _can_ pass through red-hot iron with
singular facility, but actually _does_ so whenever there is atmospheric
air on one side and carbonic oxide on the other.
For the benefit of my non-chemical readers, I may explain that
when any of our ordinary fuel is burned, there are two products of
carbon combustion, one the result of complete combustion, the other
of semi-combustion—carbonic acid and carbonic oxide—the former,
though suffocating when breathed alone or in large proportion, is
not otherwise poisonous, and has no disagreeable odor; it is in fact
rather agreeable in small quantities, being the material of champagne
bubbles and of those of other effervescing drinks. Carbonic oxide, the
product of semi-combustion, is quite different. Breathed only in small
quantities, it acts as a direct poison, producing peculiarly oppressive
headaches. Besides this, it has a disagreeable odor. It thus resembles
many other products of imperfect combustion, such as those which are
familiar to everybody who has ever blown out a tallow candle, and left
the red wick to its own devices.
On this account alone any kind of iron stove capable of becoming
red-hot should be utterly condemned. If Englishmen did their traveling
in North Europe in the winter, their self-conceit respecting the
comfort of English houses would be cruelly lacerated, and none such
would perpetrate the absurdity of applying the name of “German stove”
to the iron fire-pots that are sold as stoves by English ironmongers.
As the Germans use so great a variety of stoves, it is scarcely correct
to apply the title of German to any kind of stove, unless we limit
ourselves to North Germany. There, and in Sweden, Denmark, Norway, and
Russia, the construction of stoves becomes a specialty. The Russian
stove is perhaps the most instructive to us, as it affords the greatest
contrast to our barbarous device of a hole in the wall into which fuel
is shoveled, and allowed to expend nine-tenths of its energies in
heating the clouds, while only the residual ten per cent does anything
towards warming the room. With the thermometer outside below zero, a
house in Moscow or St. Petersburg is kept incomparably more warm and
comfortable, and is _better_ ventilated (though, perhaps, not so
_much_ ventilated) than a corresponding class of house in England,
where the outside temperature is 20 or 30 degrees higher, and this with
a consumption of about one-fourth of the fuel which is required for the
production of British bronchitis.
This is done by, first of all, sacrificing the idiotic recreation of
fire-gazing, then by admitting no air into the chimney but that which
is used for the combustion of the fuel; thirdly, by sending as little
as possible of the heat up the chimney; fourthly, by storing the heat
obtained from the fuel in a suitable reservoir, and then allowing it
gradually and steadily to radiate into the apartment from a large but
not overheated surface.
The Russian stove by which these conditions are fulfilled is usually
an ornamental, often a highly artistic, handsome article of furniture,
made of fire-resisting porcelain, glazed and otherwise decorated
outside. Internally it is divided by thick fire-clay walls into several
upright chambers or flues, usually six. Some dry firewood is lighted
in a suitable fireplace, and is supplied with only sufficient air
to effect combustion, all of which enters below and passes fairly
through the fuel. The products of combustion being thus undiluted with
unnecessary cold air, are very highly heated, and in this state pass up
compartment or flue No. 1; they are then deflected, and pass down No.
2; then up No. 3, then down No. 4, then up No. 5, then down No. 6. At
the end of this long journey they have given up most of their heat to
the 24 heat-absorbing surfaces of the fire-clay walls of the six flues.
When the interior of the stove is thus sufficiently heated, the
fire-door and the communication with the chimney are closed, and the
fire is at once extinguished, having now done its day’s work; the
interior of the stove has bottled up its calorific force, and holds it
ready for emission into the apartment. This is effected by the natural
properties of the walls of the earthenware reservoir. They are bad
conductors and good radiators. The heat slowly passes through to the
outside of the stove, is radiated into the apartment from a large and
moderately-heated surface, which affords a genial and well-diffused
temperature throughout.
There is no scorching in one little red-hot hole, or corner, or box,
and freezing in the other parts of the room. There are no draughts, as
the chimney is quite closed as soon as the heat reservoir is supplied.
If one of these heat reservoirs is placed in the hall, where it may
form a noble ornament and can easily communicate with an underground
flue, it warms every part of the house, and enables the Russian to
enjoy a luxurious temperate climate indoors in spite of arctic winter
outside.
In a house thus warmed and free from draughts or blasts of cold air,
ventilation becomes the simplest of problems. Nothing more is required
than to provide an inlet and outlet in suitable places, and of suitable
dimensions, when the difference between the specific gravity of the
cold air without and warm air within does all the rest. Nothing is
easier to arrange than to cause all the entering air to be warmed
on its way by the hall stove, and to regulate the supply which each
apartment shall receive from this general or main stream by adjusting
its own upper outlet. In our English houses, with open chimneys, all
such systematic, scientific ventilation is impossible, on account of
the dominating, interfering, useless, and comfort-destroying currents
produced by these wasteful air-shafts.
I should add that the Russian porcelain reservoirs may be constructed
for a heat supply of a few hours or for a whole day, and I need say
nothing further in refutation of the common British prejudice which
confounds so admirable and truly scientific a contrivance with the iron
fire-pot above referred to.
There is another kind of stove, which, for the sake of distinction,
I may call Scandinavian, as it is commonly used in Norway, Sweden,
and Denmark, besides some parts of North Germany. This is a tall,
hollow iron pillar, of rectangular section, varying from three to
six feet in width, and rising half-way to the ceiling of the room,
and sometimes higher. A fire is lighted at the lower part, and the
products of combustion, in their way upwards, meet with horizontal
iron plates, which deflect them first to the right, then to the left,
and thus compel them to make a long serpentine journey before they
reach the chimney. By this means they give off their heat to the
large surface of iron plate, and enter the chimney at a comparatively
low temperature. The heat is radiated into the apartment from the
large metal surface, no part of which approaches a red-heat. A further
economy is commonly effected by placing this iron pillar in the wall
separating two rooms, so that one of its faces is in each room. Thus
two rooms are heated by one fire. One of these may be the kitchen,
and the same fire that prepares the food may be used to warm the
dining-room. The fire-worshiper is of course deprived of his “cheerful”
occupation of staring at the coals, and he also loses his playthings,
as neither poker, tongs, nor coal-scuttle are included in the furniture
of an apartment thus heated. People differently constituted consider
that an escape from the dust, dirt, and clatter of these is a decided
advantage.
Of course these stoves of our northern neighbors are costly—may be
very costly when highly ornamental. The stove of a Norwegian “bonder,”
or peasant proprietor, costs nearly half as much as the two-roomed
wooden house in which it is erected, but the saving it effects renders
it a good investment. It would cost 100_l._ or 200_l._ to fit up an
English mansion with suitable porcelain stoves of the Russian pattern,
but a saving of 20_l._ a year in fuel would yield a good return as
regards mere cost, while the gain in comfort and healthfulness would
be so great that, once enjoyed and understood, such outlay would be
willingly made by all who could afford it, even if no money saving were
effected.
Only last week I was discussing this question in a railway carriage,
where one of my fellow-passengers was an intelligent Holsteiner. He
confirmed the heresy by which I had shocked the others, in exulting in
the high price of coal, and wishing it to continue. He told us that
when wood was abundant in his country, fuel was used as barbarously,
as wastefully, and as inefficiently as it now is here, but that the
deforesting of the land, and the great cost of fuel, forced upon them a
radical reform, the result of which is that they now have their houses
better warmed, and at a less cost than when fuel was obtainable at one
fourth of its present cost.
Such will be the case with us also if we can but maintain the present
coal famine during one or two more winters, especially if we should
have the further advantage of some very severe weather in the meantime.
Hence the cruel wishes above expressed. The coal famine would scarcely
be necessary if we had Russian winters, for in such case our houses,
instead of being as they are, merely the most uncomfortable in North
Europe, would be quite uninhabitable. With our mild winters we require
the utmost severity of fuel prices to civilize our warming and
ventilating devices.
“BAILY’S BEADS.”
TO THE EDITOR OF THE _Times_.
SIR,—The curious breaking up of the thin annular rim of the sun which
is uncovered just before and just after totality, or which surrounds
the moon during an annular eclipse, has been but occasionally observed,
and some scepticism as to the accuracy of Baily’s observations has
lately arisen. Having attempted an explanation of the “beads,” I have
looked with much interest for the reports of the eclipse of 1870, for,
if I am right, they ought to have been well seen on this occasion. This
has been the case. We are informed that both Lord Lindsay and the Rev.
S. J. Perry have observed them, and that Lord Lindsay has set aside all
doubts respecting their reality by securing a photographic record of
their appearance.
My explanation is that they are simply sun-spots seen in profile—spots
just caught in the fact of turning the sun’s edge. All observers are
now agreed as to the soundness of Galileo’s original description of
the spots—that they are huge cavities, great rifts of the luminous
surface of the sun, many thousands of miles in diameter, and probably
some thousand miles deep. Let us suppose the case of a spot—say, 2,000
miles deep and 10,000 miles across (Sir W. Herschel has measured spots
of 50,000 miles diameter). When such a spot in the course of the sun’s
rotation reaches that part which forms the visible edge of the sun, it
must, if rendered visible, be seen as a notch; but what will be the
depth of such a notch? Only about 1-430th of the sun’s diameter. But
the apparent depth would be much less as the edge or rim of the spot
next to the observer would cut off more or less of its actually visible
depth, this amount depending upon the lateral or east and west diameter
of the spot and its position at the time of observation.
Thus, the visible depth of such a notch would rarely exceed one
thousandth of the sun’s apparent diameter, or might be much less. The
sun being globular, the edge which is visible to us is but our horizon
of his fiery ocean, which we see athwart the intervening surface as
it gradually bends away from our view. So small an indent upon this
edge would, under ordinary circumstances of observation, be rendered
quite invisible by the irradiation of the vast globular surface of the
glaring photosphere, upon which it would visually encroach.
If, however, this body of glare could be screened off, and only a line
of the sun’s edge, less than one thousandth of his diameter, remain
visible, the notch would appear as a distinct break in this curved line
of light. If a group of spots, or a great irregular spot with several
umbræ, were at such a time situated upon the sun’s edge, the appearance
of a series of such notches or breaks leaving intermediate detachments
of the visible ring of the photosphere would be the necessary result,
and thus would be presented exactly the appearance described as
“Baily’s beads.”
I have been led to anticipate a display of these beads during the
late eclipse by the fact that some days preceding it a fine group of
spots—visible to the naked eye through a London fog—were traveling
towards the eastern edge of the sun, and should have reached the limb
at about the time of the eclipse. The beads were observed by the Rev.
S. J. Perry just where I expected them to appear. I have not yet learnt
on which side of the sun they were observed and photographed by Lord
Lindsay.
Baily’s first observation of the beads was made during the annular
eclipse of May 15, 1836. That year, like 1870, was remarkable for a
great display of sun-spots. As in 1870, they were then visible to the
naked eye. I well remember my own boyish excitement when, a few weeks
before the eclipse of 1836, I discovered a spot upon the reddened face
of the setting sun—a thing I had read about, and supposed that only
great astronomers were privileged to see. The richness of this sun-spot
period is strongly impressed on my memory by the fact that I continued
painfully watching the dazzling sun, literally “watching and weeping,”
up to the Sunday of the eclipse, on which day also I saw a large spot
through my bit of smoked glass.
The previous records of these appearances of fracture of the thin line
of light are those of Halley, in his memoir on the total eclipse of
1715, and Maclauren’s on that of 1737. Both of these correspond to
great spot periods; the intervals between 1715, 1737, 1836, and 1870
are all divisible by eleven. The observed period of sun-spot occurrence
is eleven years and a small fraction.
I am anxiously awaiting the arrival of Lord Lindsay’s long-exposure
photographs of the corona, for if they represent the varying degrees of
splendor of this solar appendage, the explanations offered in Chapter
xii. of my essay on “The Fuel of the Sun” will be very severely tested
by them.
Yours respectfully,
W. MATTIEU WILLIAMS.
Woodside Green, Croydon, January 4, 1871.