THE CARBONIFEROUS SYSTEM.
“As for the earth, out of it cometh bread, and under it is turned up as
it were fire.”—JOB.
Suppose this lump of coal could speak, what would it say? Would it not
say something like this: “To get me up out of the earth involves dirt,
danger, slush, and much tallow-candle; but now you have me, let me tell
you my story, for though black I am comely, and but for me—but I
anticipate. Now and then I make a dust in your libraries, and
inadvertently shoot out sparks and firestones, but nevertheless I am of
more use to man than the old granite or the proudest Parian marble; you
may get a long way in philosophy, but you will never get beyond coal. I
am the real Koh-i-noor of the British empire; and though I can’t, like
my namesake, put on a white dress, I am nevertheless worth the soiling
of your whitest gloves. _Chemistry_ makes no discoveries without me: I
light the fire of the laboratory, and furnish man with the means of
every crucial test. _Civilization_ wants me every day on land and sea,
and though in one sense my labours end in smoke, in another they end in
commerce, progress, national brotherhood, and interchanging productions
of every clime. The _poor student_ needs me, for I light his lamp, warm
his feet, and cook his food while he is doing sweat-of-brain work for
others. And best of all, the _poor man_ is a rich man when he has me; he
knows that next of kin to good food is good fuel, and man by my help is
making such progress, that the day will come when every man will sit by
his own blazing fire, instead of seeking joy elsewhere amidst false and
pernicious excitements.”
Something like this our friend Coal would be sure to say; and that Coal
may not complain of any aloofness on our parts, let us proceed to an
examination of the carboniferous system.
“’Tis very pregnant,
The jewel that we find, we stoop and take it,
Because we see it; but what we do not see,
We tread upon, and never think of it.”
_Measure for Measure._
The carboniferous system is not all coal; underlying, and often
overlying, the coal measures, for the most part, is the mountain
limestone, a formation pre-eminently rich in marine fossils. During the
tremendous convulsions experienced by the earth immediately after the
deposition of the old red sandstone, a vast sea of lime, thick, muddy,
and hot, seems to have been poured out over a large portion of the
British islands and elsewhere. This flow of liquid lime covered and
encased many then existing animals, and we now find it full of fossils
of the crinoidean family, a few molluscs, and traces of fish. We shall
not, however, stay to examine these now, as we shall meet with them
again in the Oolite; our attention will be limited to that part of the
carboniferous system which includes only the coal measures, properly so
called.
Coal is a vegetable that, by _chemical change_ and by _mechanical
pressure_, has become a bituminous mineral; and this will render it
needful to say a word or two on the ancient vegetable kingdom. The vast
quantities[56] of remains of leaves, ferns, and stems of trees, found in
the coal measures, are not in themselves evidence sufficient of the
vegetable origin of coal; we arrive at that conclusion in consequence of
the researches of modern philosophers, who having applied the powers of
the microscope to the internal structure of coal, have discovered the
cellular and reticular construction of vegetable life beautifully
preserved, and thus previous convictions have become certainties. The
examination of the ancient vegetable kingdom is, however, attended with
much difficulty, in consequence of the total destruction in most cases
of the stems and trunks of the plants, and the entire absence, in
consequence of pressure, of all fructification on the fronds of the
ferns. If we take an existing species of fern, say the rare and delicate
“maiden-hair fern,”[57] one of the smallest and most elegant ferns of
England, we find the fructification very distinct on the under side, and
the different methods in which this fructification is arranged is now
the principal guide in the classification of ferns. But if we take a
fossil fern, say the pecopteris, found in the coal measures, we shall
see that there has been so much dislocation and crushing, that all
appearance of seed-vessels has disappeared. The following sketch will
explain this.
[Illustration:
EXTINCT FERN, AND MAIDEN-HAIR FERN.
]
“Nothing,” says Professor Ansted, “however, is more certain than that
all coal was once vegetable; for in most cases the woody structure may
be detected under the microscope, and this, if not in the coal in its
ordinary state, at least in the burnt ashes which remain after it has
been exposed to the action of heat, and has lost its bituminous and
semi-crystalline character. This has been too well and too frequently
proved by actual experiment to require more than the mere statement of
the fact.” And here let us say a few words, which to a few perhaps may
have the charm of novelty, about the economic history of coal; for as
Cowper says that the first curse, “labour,” has, by God’s blessing on
it, been “softened into mercy,” so do we add also, in his words,
heartily subscribing to their truth,—
“Thus studied, used, and consecrated thus,
On earth what is, seems formed indeed for us;
Not as the plaything of a froward child,
Fretful unless diverted and beguiled;
But as scale, by which the soul ascends
From mighty means to more important ends;
Securely, though by steps but rarely trod,
Mounts from inferior beings up to God;
And sees, by no fallacious light or dim,
Earth made for man, and man himself for Him.”
How long coal has been known and used, we cannot certainly tell, but a
writer in Lardner’s Cabinet Cyclopædia states that the first mention of
coal is in the pages of one Theophrastus, who was, it seems, a pupil of
Aristotle. He says, “Those fossil substances that are called coals,”
(Greek, ἄνθραξ) “and are broken for use, are earthy; they kindle,
however, and burn like wood coals; they are found in Liguria and in the
way to Olympias over the mountains, and are used by the smiths.” Cæsar,
although he speaks of the metals of the British isles, does not once
mention its coal; but it seems more than likely that it was both known
and used by the Romans during their occupation of Britain. Horsley, in
his “Britannia Romana,” says of Benwell, a village near
Newcastle-on-Tyne, “There was a coalry not far from this place, which is
judged by those who are best skilled in such affairs to have been
wrought by the Romans; and, in digging up the foundations of one of the
Roman walled cities, coal cinders very large were dug up, which glowed
in the fire like other coal cinders, and were not to be known from them
when taken up.”
During the time of the Saxons, we find ourselves on less doubtful
ground. In a grant made to the monks of Peterborough Abbey for one
night’s annual entertainment, those good old souls had, we find, “ten
vessels of Welsh ale, two vessels of common ale, sixty cartloads of
wood, and twelve cartloads of _fossil coal_,” (_carbonum fossilium_.)
The Danes had so much fighting on hand, that they troubled themselves
neither with coal nor civilization; and we know little of our English
diamond until we come to Henry the Third’s reign, when, in 1239, a
charter was granted to the inhabitants of Newcastle-on-Tyne to dig
coals, and we find the coal called for the first time “_carbo maris_,”
or sea-coal, a term retained through all the succeeding centuries. About
this time chimneys came into fashion. As long as people burnt wood they
scarcely needed chimneys, but coal introduced chimneys, to say nothing
of steamboats and railroads. The Archbishop of Canterbury, who at that
time used to reside alternately at Croydon and at Lambeth, had by royal
permission thirty cartloads of “sea-borne coal” annually delivered at
his archiepiscopal palace, because, says the historian, “for his own
private use in his own chamber he now had the convenience of chimneys.”
The smoke nuisance of that day deserves a passing notice. Smoke was then
with many a grand luxury. Old Hollingshed says, “Now we have many
chimneys, yet our tenderlings do complain of rheums, and catarrhs, and
poses. Once we had nought but rere-doses,[58] and our heads did never
ake. For the smoke of those days was a good hardening for the house, and
a far better medicine to keep the good man and his family from the quack
or the pose, with which then very few were acquainted. There are old men
yet dwelling in the village where I remain, who have noted how the
multitude of chimneys do increase, whereas in their young days, there
was not above two or three, if so many, in some uplandish towns of the
realm, and peradventure in the manor places of some great lords; but
each one made his fire against a rere-dose in the hall, where he dined
and dressed his meat. But when our houses were built of willow, then we
had oaken men; but now that our houses are made of oak, our men are not
only become willow, but a great many altogether men of straw, which is a
sore alteration.”
Leaving this digression, let us try and get a bird’s-eye view of the
coal-fields of the British Isles. If we commence in Devonshire, we find
there the Devonian culms, or Bovey Tracey coal, lying near the surface
of the ground, and of little except local use. Crossing over the Bristol
Channel, we come into Pembrokeshire, to the Welsh basin, remarkable
because thence we mostly get our anthracite coal. Thence we pass on to
the Derbyshire coal-fields, that go with little interruption into
Scotland, averaging 200 miles in length, and about 40 in width,—once
mighty tropical swamps, jungles, and forests, now become chief minerals
of commerce. Included in this last immense field is the great Newcastle
coal district, the most celebrated of any, supplying almost all the
south of England, and nearly all London, with their best coals; and the
Scotch carboniferous system, celebrated for its numerous fossils, and
for its general base of old red sandstone. In addition to which there is
the Irish carboniferous system, occupying as much as 1,000 square miles,
but of an inferior quality, and not likely to be of any great economical
importance.
In the words of Professor Ansted, we add: “This account of the coal-beds
gives a very imperfect notion of the quantity of vegetable matter
required to form them; and, on the other hand, the rate of increase of
vegetables, and the quantity annually brought down by some great rivers
both of the eastern and western continents, is beyond all measure
greater than is the case in our drier and colder climates. Certain kinds
of trees which contributed largely to the formation of the coal, seem to
have been almost entirely succulent,[59] and capable of being squeezed
into a small compass during partial decomposition. This squeezing
process must have been conducted on a grand scale, and each bed in
succession was probably soon covered up by muddy and sandy
accumulations, now alternating with the coal in the form of shale and
gritstone. Sometimes the trunks of trees caught in the mud would be
retained in a slanting or nearly vertical position, while the sands were
accumulating around them; sometimes the whole would be quietly buried,
and soon cease to exhibit any external marks of vegetable origin.”[60]
There are various kinds of coal on which we may bestow a few words.
There is _anthracite_, or non-bituminous coal, and which, therefore,
burns without flame or smoke, and is extensively used in malting; and
_sea-coal_, which is highly bituminous, and which gives forth so much
flame and smoke, that in the good old times of 1306, Parliament forbad
its use in London by fine and by demolition of all furnaces in which it
was burnt, because “this coal did corrupt the air with its great smoke
and stink;” and _cannel-coal_, the etymology of which, they say, is firm
the word candle, because in many parts of Lancashire the poor use it in
place of oil or tallow for lights; and _jet_, sometimes called black
amber, which in France employs about 1,200 men in one district, in
making earrings, rosaries, and other ornaments; and last of all, there
is wood passing into coal called _lignite_, found only in the Devonshire
culms.
Having thus glanced at the natural history and varieties of coal, we may
here try and realize the flora of the carboniferous era. An examination
of the fossils of this period enables us to come to undoubted
conclusions concerning the trees and plants of that era, so that it is
no mere dream to look upon a picture like the following, and see in it a
landscape of the coal-forming time of the British islands.
[Illustration:
FLORA OF THE COAL MEASURES RESTORED.
]
The sun then poured down his golden beams of heat and light, and a
tropical climate prevailed in our now cold and humid England. The
mountain tops were gilded with his rays; a vast ocean studded with
islands, and these crowned with gigantic palms and ferns, then covered
our northern hemisphere. In that ocean but few fish were to be found,
though many rare molluscous animals swam to and fro, enjoying their
brief term of life, and discharging all their appropriate functions.
Mountain streams discharged their muddy waters into this ocean, leaving
along their margin course broken trees, vegetables, grasses and ferns.
The giant Lepidodendron looked like a monarch of the ancient world,
while around him smaller ferns, vying with each other in beauty and
grace, grew, “first the blade” and then the ripened frond, until, in
obedience to the great law of organic life, they died and decayed, and
became material for the coming man’s future use. But amidst all this
prodigal luxuriousness of the vegetable world, there appears to have
been neither bird nor beast to break the monotony of the scene; all was
silent as the grave—rank, moist verdure below; magnificent ferns and
palms above, and the stillness of death on every side.[61]
[Illustration: Fossil]
[Illustration: Fossil]
Let us, however, glance at the principal ferns, whose fossil remains we
have often found at the mouth of many a coalpit thrown out among the
waste. The uncouth names given to them, uncouth only in appearance, must
not deter the reader from his acquaintance with their peculiarities; for
are not the names of botanical science almost, if not quite, as
repellent at first? This star-shaped beauty, (1) the _asterophyllite_,
(from _aster_, a star, and _phyllon_, a leaf,) was a common one; this
(2) is the _sphenopteris_ (from _sphēn_, a wedge, and _pteron_, a wing),
so named from a fancied resemblance of the petals of the frond to a
wedge; the next (3) is the _pecopteris_ (from _pekos_, a comb, and
_pteron_, a wing), from a resemblance of the frond to the teeth of a
comb; the next (4) is the _odontopteris_ (from _odous_, a tooth, and
_pteron_, a wing), and in this the frond is something like the jaws of a
shark bound together by a central stem, from which they diverge; and the
last (5), our favourite, is the _neuropteris_ (from _neuros_, a nerve,
and _pteron_, a wing), on account of the exquisite beauty with which the
fibres, like nerves, distribute themselves.
“Besides the ferns, then growing to a great size, there were other
plants whose modern representatives are uniformly small; but as the
resemblance in this case is simply one of general form, and the great
majority of other trees seem to possess no living type to which they can
be referred, it is by no means impossible that these also may be
completely lost. One example of them is seen in a plant, fragments of
which are extremely common in the coal measures, and which has been
called _calamite_.[62] The remains of calamites consist of jointed
fragments, which were originally cylindrical, but are now almost always
crushed and flattened. They resemble very closely in general appearance
the common jointed reed, growing in marshes, and called _equisetum_, or
mare’s tail; but instead of being confined to a small size, they would
seem to have formed trees, having a stem more than a foot in diameter,
and jointed branches and leaves of similar gigantic proportions. They
were evidently soft and succulent, and very easily crushed. They seem to
have grown in great multitudes near the place where the coal is now
accumulated; and though often broken, they seldom bear marks of having
being transported from a distance.”[63] The fossils of the carboniferous
system here figured we found not long since in the neighbourhood of
Stockport.
[Illustration:
CALAMITES.
]
[Illustration:
CALAMITE.
]
[Illustration:
STIGMARIA FICOIDES.
]
This chapter on the carboniferous system must not be further lengthened.
We do not aspire to teach the science of geology; we aim only to impart
such a taste for it as shall lead the reader to consult our master works
on this subject, and if we succeed in this humble but useful aim, our
purpose will be fully answered. Only in reference to the economic uses
of coal, we will quote the following, copied, we believe, from the
“Athenæum” some time since, but unfortunately copied without reference
to its original; a lesson for common-place-book keepers. The writer in
speaking of coal-gas says: “The consumption of gas is enormous. The
following statistics give us an insight into the extent which this
branch of industry has attained. In England 6,000,000 tons of coals are
annually employed for the manufacture of gas, and from 12,000,000 to
15,000,000 pounds sterling expended in its production. In London alone
500,000 tons of coals are annually used, producing 4,500,000,000 cubic
feet of gas, and 500,000 chaldrons of coke; of the latter, 125,000
chaldrons are consumed in manufacturing the gas, and the remainder sold
for fuel. Upwards of half-a-million houses in London burn gas, and the
length of the main arteries for conveying it is 1,600 miles. The capital
employed in the metropolis is 4,000,000_l._ The manufacture of coal-gas
for the purpose of illumination affords one of the most striking
instances of the triumphs of science when enlisted in the divine cause
of civilization. Looking at it as a whole, and regarding the ingenuity
evinced in the construction of apparatus, the chemical skill and beauty
displayed in the process, and the very valuable purposes to which it is
applied, it forms one of the most beautiful, curious, and useful of our
manufactures; and probably there is no subject of a manufacturing
character in the present day which more engages public attention,
coal-gas having now become not a mere luxury, or even convenience, but
an absolute necessary. In the words of my late colleague and friend, Dr.
Hofmann, ‘The extent to which the use of gas has affected the arts and
manufactures in this country, can only be conceived by those who are
aware of its innumerable applications in the double capacity of giving
light and heat. To our experimental chemists the benefits afforded by
gas cannot be overrated, more especially in England, where the price of
spirits of wine is so exorbitant. But for the use of gas in the
laboratory, the progress of chemistry in this country must have been
greatly retarded.’
“In speaking of the general influence of the manufacture of coal-gas, it
is impossible to leave unnoticed the number of hands daily engaged in
raising whole strata of coal, in loading and navigating the fleets
employed in conveying it, not only to the different parts of this
kingdom, but to foreign countries, which consume a larger quantity of
English coal for the production than is generally known. The extension
of the gas enterprise produced a sensible effect on the ironworks, by
the vast number of retorts, the stupendous gas-holders, and endless
pipes required for generating, storing, and conveying it.
“Several other branches of trade were also forced into increased
activity, and even new trades sprung up in consequence of the extended
use of gas. The substances produced in the purification of gas naturally
attracted the attention of the gas manufacturer; and chemistry soon
pointed out valuable purposes to which they might be applied. The oily
matter, which separates as a secondary product in the distillation of
coal, yielded, when purified in its more volatile portion, the most
convenient solvent for caoutchouc; another part of it was found to be an
efficient preservative of timber, and the pitchy residue formed the
chief ingredient of an excellent substitute for the flag stones of our
pavements; while the ammoniacal liquors were found useful in improving
the fertility of land. Thus, after the lapse of countless ages, was the
nitrogen of petrified fern forests resuscitated in the ammoniacal
liquors of the gas-works, to vegetate once more and increase the produce
of our corn fields.”
[Illustration:
SIR HUMPHREY DAVY’S LAMP, AND MINER AT WORK.
]
“All nature feels the secret power,
And through eternal change obeys
Up from the deepest region creeps
The trace of life of former days.”
_Faust._