Coal and Coal-Mines
There are few subjects of more importance, and few less known or thought about, than our coal-mines. Coal is one of our greatest blessings, and certainly one originating cause of England’s greatness and wealth. It has given us a power over other nations, and vast sums of money are yearly brought to our country from abroad in exchange for the coal we send. Nearly £17,000,000 is the representative value of the coal raised every year at the pit’s mouth, and £20,000,000 represent its mean value at the various places of consumption. The capital invested in our coal-mining trade, apart from the value of the mines themselves, exceeds £20,000,000 sterling, and the amount of coal annually extracted from the earth is over 70,000,000 of tons. Taking the calculation of a working miner—J. Ellwood, Moss Pit, near Whitehaven—we may state, that if 68,000,000 tons were excavated from a mining gallery 6 feet high and 12 feet wide, that gallery would be not less than 5128 miles, 1090 yards, in length; or, if this amount of coal were erected in a pyramid, its square base would extend over 40 acres, and the height would be 3356 feet.
There are grounds for believing that the produce of the various coal-fields of the world does not at present much exceed 100,000,000 of tons annually, and therefore our own country contributes more than three-fifths of the total amount. If we divide the coal-yielding counties of Britain into four classes, so as to make nearly equal amounts of produce, we find that Durham and Northumberland yield rather more every year than seven other counties, including Yorkshire. Derbyshire, again, produces more than eight other counties, and nearly as much as the whole of North and South Wales, Scotland, and Ireland—the yield of the latter being about 17,000,000 of tons, and that of the two first-named about 16,000,000 of tons.
In 1773 there were only 13 collieries on the Tyne, and these had increased to upwards of 30 in 1800. The number of collieries in 1828 had increased to 41 on the Tyne, and 18 on the Wear, in all 59, producing 5,887,552 tons of coal. The out-put of coal in Northumberland and Durham in 1854 was no less than 15,420,615 tons, and now in these two counties there are 283 collieries. Mining began on the Tyne and continued on the Wear, where the industry has been largely developed. There are in all about 57 different seams in the Great Northern coal-field, varying in thickness from 1 inch to 5 feet 5 inches and 6 feet, and these seams comprise an aggregate of nearly 76 feet of coal. Taking the area of this field to be 750 square miles—a most probable estimate—we may classify the contents as household coal, steam coal, or those employed in steam-engine boilers, and coking coal, employed for making coke and gas. Of household coal there is only 96 square miles out of the total 750, all the remainder being steam or coking and gas coal. The greater part even of this 96 square miles has been worked out on the Tyne, and the supply is rapidly decreasing also on the Wear, where the largest bulk of the household coal lies. The collieries of the Tees possess but six square miles out of the 96, as far as we at present know. Turning, however, to that part of the coal-field regarded as precarious, and consisting of first, second, and third-rate household coal, we have for future use 300 square miles. London was formerly supplied from the pits east of Tyne Bridge, where is the famous Wallsend Colliery, which gave the name to the best coal. That mine is now drowned out, and, like the great Roman Wall, at the termination of which it was sunk, and from which it derived its name, is now an antiquity. There is now no Wallsend coal, and the principal part of the present so-called coal comes from the Wear, but the seam which supplied that famous pit is continued into Durham, and that seam, or its equivalent, sends a million or two of tons every year into London. The supply, however, in this district is rapidly decreasing. Careful calculations have been made as to the probable duration of this coal, of which the following is a summary. The workable quantity of coal remaining in the ten principal seams of this coal-field is estimated at 1,876,848,756 Newcastle chaldrons (each 35 cwt.). Deducting losses and underground and surface waste, the total merchantable round or good-sized coal will be 1,251,232,507 Newcastle chaldrons. Proceeding on this estimate, formed by Mr. Grunwith in 1846, we may arrive at the probable duration of the supplies: taking the future annual average of coal raised from these seams to be 10,000,000 of tons—and this is under the present rate—the whole will be exhausted in 331 years. A still later estimate was made by Mr. T.G. Hall in 1854, and he reckoned the quantity of coal left for future use at 5,121,888,956 tons; dividing this by 14,000,000 of tons as the annual consumption, the result would be 365 years; and should the annual demand arrive at 20,000,000 of tons, the future supply of this famous coal-field would continue for 256 years. The total available coal (1871) in the British coal-fields, at depths not exceeding 4000 feet, and in seams not less than 1 foot thick, is 90,207,285,398 tons, and taking into account seams which may yet become available, lying under the Permian, New Red Sandstone, and other superincumbent strata, this estimate is increased to 146,480,000,000 of tons. This quantity, at the present annual rate of production throughout the country—namely, 123,500,000 tons—would last 1186 years. Other estimates of various kinds relative to our coal supply have been put forth: some have asserted that, owing to increasing population and increasing consumption in manufactures, it will be exhausted in 100 years, and between this extreme and that of 1186 years there are many other conjectures and estimates.
In the United States there are about 120,000 square miles underlaid by known workable coal-beds, besides what yet remains to be discovered; while on the cliffs of Nova Scotia the coal-seams can be seen one over the other for many hundred feet, and showing how the coal was originally formed. With this immense stock of fuel in the cellars of the earth, it seems evident that we need not trouble our minds or be anxious as to the duration of our coal supply. Besides, the conversion of vegetable matter into coal seems to be going on even now. In the United States there are peat-bogs of considerable extent, in which a substance exactly resembling cannel coal has been found; and in some of the Irish peat-beds, as also in the North of Scotland, a similar substance has been discovered, of a very inflammable nature, resembling coal.
Yes! what could have produced this singular-looking, black, inflammable rock? How many times was this question asked before Science could return an answer? This she can now do with confidence. Coal was once growing vegetable matter. On the surface of the shale, immediately above the coal, you will find innumerable impressions of leaves and branches, as perfect as artist ever drew. But how could this vegetable matter ever accumulate in such masses as to make beds of coal of such vast extent, some not less than 30 feet thick? It would take 10 or 12 feet of green vegetable matter to make 1 foot of solid coal. Let us transport ourselves to the carboniferous times, and see the condition of the earth, and this may assist us to answer the question. Stand on this rocky eminence and behold that sea of verdure, whose gigantic waves roll in the greenest of billows to the verge of the horizon—that is a carboniferous forest. Mark that steamy cloud floating over it, an indication of the great evaporation constantly proceeding. The scent of the morning air is like that of a greenhouse; and well it may be, for the land of the globe is a mighty hothouse—the crust of the earth is still thin, and its internal heat makes a tropical climate everywhere, unchecked by winter’s cold, thus forcing plants to a most luxurious growth.
Descend, and let us wander through this forest and examine it more closely. What strange trees are here! No oaks, no elms, or ash, or chestnut—no trees that we ever saw before. It looks as if the plants of a boggy meadow had shot up in a single night to a height of 60 or 70 feet, and we were walking among the stalks—a gigantic meadow of ferns, reeds, grasses, and club-mosses. A million columns rise, so thick at the top that they make twilight at mid-day, and their trunks are so close together we can scarcely edge our way between them, whilst the ground is carpeted with trailing plants completely interwoven. What strange trees they are! Beneath us lies an accumulation of vegetable matter more than 200 feet in thickness—the result of the growth and decay of plants in this swamp for centuries. All things are here favourable for the growth of vegetation—the great heat of the ground causes water to rise rapidly in vapour, and this again descends in showers, supplying the plants with moisture continuously. The air contains a large proportion of carbonic acid gas, poison to animals but food to plants, which, by means of its aid, build up their woody structure. Winds at times level these gigantic plants, for their hold on the earth is feeble, and thus the mass goes on increasing.
We are now on the edge of a lake abounding with fish, whose bony scales glitter in the water as they pursue their prey. Lying along the shore are shells cast up by the waves, and there are also seen the tracks of some large animals. How like the impression of a man’s hand some of these tracks are! The hind-feet are evidently much larger than the fore-feet. There is the frog-like animal which made them, and what a size! It must be six feet long, and its head looks like that of a crocodile, for its jaws are furnished with formidable rows of long, strong, sharp, conical teeth.
The continued growth and decomposition of the vegetation during long ages must have produced beds like the peat-deposits of America and Great Britain. In the Dismal Swamp of Virginia there is said to be a mass of vegetable matter 40 feet in thickness, and on the banks of the Shannon in Ireland is a peat-bog 3 miles broad and 50 feet deep. When conditions were so much more favourable for these deposits, beds 400 feet in thickness may easily have been produced. This accumulated mass of vegetable matter must be buried, however, before we can have a coal-bed. How was this accomplished? The very weight of it may have caused the crust of the earth to sink, forming a basin into which rivers, sweeping down from the surrounding higher country, and carrying down mud in their waters, the weight of which, deposited upon the vegetable matter, pressed and squeezed it into half its original compass. Sand carried down subsequently in a similar manner, and deposited upon the mud, pressed it into shale, and the vegetable matter, still more reduced in volume by this additional pressure, is prepared for its final conversion into shale. In time the basin becomes shallow from the decomposition of sediment on its bottom, and then we have another marsh with its myriad plants; another accumulation of vegetable matter takes place, which by similar processes is also buried. Where thirty or forty seams of coal have been found one below another, we have evidence of land and water thus changing places many times.
When vegetable matter is excluded from air and under great pressure, it decomposes slowly, parting with carbonic acid gas; and is first changed into lignite or brown coal, and then into bituminous coal, or the soft coal that burns with smoke and flame. I have been in a coal-mine where the carbonic acid gas, pouring from a crevice in the coal, put out a lighted candle. The high temperature to which the coal has been subjected when buried at great depths has also probably assisted in producing this change; and where that temperature has been very high, the coal by the influence of the heat having parted with its inflammable gases, we have the hard or anthracite coal, which burns with little or no flame and without smoke. It is indeed coal made into coke under tremendous pressure, and this is the kind of coal which Americans use exclusively in their dwelling-houses and monster hotels.
It was at first supposed that the plants of the carboniferous times were bamboos, palms, and gigantic cactuses, such as are now found in tropical regions, but a more careful examination of them shows that, with the exception of the tree-fern now found in the tropics, they differ from all existing trees. A large proportion of the plants of the coal-measures were ferns, some authorities say one-half. From their great abundance we may infer the great heat and moisture of the atmosphere at the time when they grew, as similar ferns at the present day are only found in the greatest abundance on small tropical islands where the temperature is high. Coal often contains impressions of fern leaves and palm-like ferns—no less than 934 kinds are drawn and described by geologists. Many animals and insects are found in the coal, such as large toad-like reptiles with beautiful teeth, small lizards, water lizards, great fish with tremendous jaws, many insects of the grasshopper tribe, but none of these are of the same species as those found now living on this globe.
Wood, peat, brown coal, jet, and true coal, are chemically alike, differing only in their amount of oxygen, due to the difference of compression to which they were subjected. The sun gave his heat and light to the forests now turned into coal, and when we burn it ages afterwards, we revive some of the heat and light so long untouched. Stephenson once remarked to Sir Robert Peel, as they stood watching a passing train: “There goes the sunshine of former ages!”
COST OF WORKING.
Having thus stated shortly the origin and extent of the coal of this country, more particularly that of the northern coal-fields of Northumberland and Durham, I think it may be interesting to say something of the cost at which this valuable article is obtained, as I am sure few are at all aware of the vast sums of money that have to be expended before we can sit down by our comfortable firesides, with a cold winter night outside, and read our book, or have our family gathered round us; and few know the danger and hardship of the bold worker who risks his life to procure the coal. The first step is to find out if there is coal. This done, the next is to get at it, or, as it is termed, to win the coal. The process is to sink a shaft, and this is alike dangerous, uncertain, and very costly. The first attempt to sink a pit at Haswell in Durham was abandoned after an outlay of £60,000. The sinkers had to pass through sand, under the magnesian limestone, where vast quantities of water lay stored, and though engines were erected that pumped out 26,700 tons of water per day, yet the flood remained the conqueror. This amount seems incredible, but such is the fact. At another colliery near Gateshead (Goose Colliery), 1000 gallons a minute, or 6000 tons of water per day, were pumped out, and only 300 tons of coal were brought up in the same time, and thus the water raised exceeded the coal twenty times. The most astonishing undertaking in mining was the Dalton le Dale Pit, nine miles from Durham. On the 1st June 1840 they pumped out 3285 gallons a minute. Engines were erected which raised 93,000 gallons a minute from a depth of 90 fathoms or 540 feet, and this was done night and day. The amount expended to reach the coal in this pit was £300,000. Mr. Hall estimates the capital invested in the coal trade of the counties of Durham and Northumberland, including private railways, waggons, and docks for loading ships, at £13,000,000 sterling.
The great difficulty in working coal, should these upper seams fail, is not only the increase of cost in sinking further down, but the increased heat to be worked in. At 2000 feet the mine will increase in heat 28°, at 4000, 57°; to this must be added the constant temperature of 50° 5’, so that at 2000 feet it would be 78° 5’, and at 4000, 107° 5’ Fahr. By actual trial on July 17, 1857, in Duckingfield Pit, the temperature at 2249 feet was 75° 5’. From this it may be conceived in what great heat the men have to work, and the work is very hard. One may fancy from this what can be endured, but it would be next to impossible to work in a greater temperature. I can speak upon this from actual experience, as when down the Lady Londonderry Pit the temperature was 85°, and here the men worked naked. Another great source of expense and anxiety lies in keeping up the roof, as, from the excessive pressure, the roof and floor are always inclined to come together, and props must therefore be used, and these in some pits cost as much as £1500 a year. To digress for a moment, an amusing story is told of Grimaldi, the celebrated clown, when paying a visit to a coal-pit. Having gone some way through the mine, a sudden noise, arising from the falling of coal from the roof, caused him to ask the reason of the noise. “Hallo!” exclaimed Grimaldi, greatly terrified, “what’s that?” “Hech!” said his guide, “it’s only a wee bit of coal fallen down—we have that three or four times a day.” “Then I’ll thank you to ring for my basket, for I’ll stop no longer among the wee bits of falling coal.” This “wee bit” was about three tons’ weight. A large proportion of the sad accidents in coal-mines is caused by these falls of the roof, which give no warning, but suddenly come down and crush to death those who happen to be near.
MODE OF WORKING.
The cost of working having thus been given, I wish now to lay before you an explanation of the method of working and bringing the coal to the surface. It may not be uninteresting to mention how many men are employed in this work, as the number is very large. Coal was not formerly excavated by machinery, but it is so now, and therefore hands must be had. The number of men employed in the mines of county Durham in 1854 was 28,000; of these, 13,500 were hewers, winning several thousand tons of coal daily. Of the remainder, 3500 were safety-staff men, having, besides, 1400 boys belonging to their staff; 2000 were off-hand men, for bargain work or other duties; 7600 lads and boys, working under the various designations of “putters,” or pushers of coal-tubs, underground “drivers,” “marrows,” “half-marrows,” and “foals,” these latter terms being local, and significant of age and labour. For Northumberland must be added 10,536 persons, and Cumberland 3579, making a total for these three counties of upwards of 42,000 persons labouring in and round our northern collieries. The average that each hewer will raise per day is from two to three tons in thin, and three to four tons in thick seams. The largest quantity raised by any hewer on an average of the colliers of England is about six tons a day of eight hours. The mode of working is very laborious, as the majority of seams of coal being very thin—that is to say, not more than two feet thick—the worker of necessity is obliged to work in a constrained position, often lying on his side; and you can fancy the labour of using a pick in such a position. To get an idea of the position, just place yourself under a table, and then try to use a pick, and it will give you a pretty clear idea of the comfortable way in which a great part of our coal is got, and this also at a temperature of 86° in bad air. The object, of course, of the worker is to take nothing but coal, as all labour is lost that is spent in taking any other material away. The man after a time gets twisted in his form, from being constantly in this constrained position, and, in fact, to sit upright like other men is at last painful. Then an amount of danger is always before him, even in the best regulated and ventilated pits. This danger proceeds from fire-damp, as one unlucky stroke of the pick may bring forth a stream of carbureted hydrogen gas, inexplosive of itself, but if mixed with eight times its bulk of air, more dangerous than gunpowder, and which, if by chance it comes in contact with the flame of a candle, is sure to explode, and certain death is the result—not always from the explosion itself, but from the after-damp or carbonic acid gas which follows it.
Upwards of 1500 lives are yearly lost from these causes, and not less than 10,000 accidents in the same period show the constant danger that the miner is exposed to. It would appear that England has more deaths from mining accidents than foreign countries, as Mr. Mackworth’s table will show:—
| Prussia | 1.89 per 1000 | |
| Belgium | 2.8 | ″ |
| England | 4.5 | ″ |
| Staffordshire | 7.3 | ″ |
This statement shows that more care is wanted in this last-named county especially, as I find that the yield of coal in Belgium is half as much as in England. Long working in the dark, if one may so speak, is a cause of serious detriment to the sight, and the worker also suffers much from constantly inhaling the small black dust, which in course of time affects the lungs, causing what is known as “miner’s asthma.” Without going further into the unhealthy nature of the miner’s work, it may be interesting to mention something of the actual process, and having myself been an eye-witness of it, I will explain it as shortly as I can. The workers having arrived at the pit-mouth at their proper hours—for the pit is worked by shifts, and consequently is generally worked day and night—the first operation is for each to procure his lamp from the lamp-keeper, receiving it lighted and locked; this is found to be necessary, as from the small light given by the Davy-lamp the men are often tempted to open them, and some are even, so foolhardy as to carry their lamp on their cap and a candle in the hand, and hence a terrible explosion may take place. A few words on the Davy-lamp, which came into use about sixty years ago, may not be out of place here. This safety-lamp of the miner not only shows the presence of gas, but prevents its explosion. It is constructed of gauze made of iron-wire one-fortieth to one-sixtieth of an inch in diameter, having 784 openings to the inch, and the cooling effect of the current passing through the lamp prevents the gas taking fire. If we pour turpentine over a lighted safety-lamp, it will show black smoke, but no flame. Provided with his lamp, the miner takes his place with others in the tub, which conveys him with great rapidity to the bottom of the shaft. Here landed, he takes his way to the workings, some of these, in large pits, being two miles from the bottom of the shaft. To a novice this is not easy, as you have to walk in a crouching manner most part of the way. Once there, he begins in earnest, and drives at his pick for eight hours, the monotony only relieved by his gathering the products into small railway waggons or tubs to be removed. This is done mostly by boys, but in the larger mines by ponies of the Shetland and other small breeds. The tubs are taken to a part of the mine where, if one may so speak, the main line is reached, and then formed into trains, and taken to the shaft by means of an endless rope worked by an engine in the pit. In accomplishing all this work, great care has to be taken that the current of air is not changed or stopped. This is effected by means of doors placed in various parts of the mine, so as to stop the current and drive it in the required direction. These doors are kept by boys, whose duty it is to open and close them for the passage of the coal tubs. Those boys are often allowed no light, and sit in a hole cut in the side of the road near to the doors. Upon their carefulness the safety of the mine in a great measure depends, as if they neglect to shut the door the current of air is changed. I have been told that these boys are subject to accidents no less than the workers, for, sitting in the dark, and often alone for hours, they are very apt to go to sleep. To ensure being awoke at the proper time, they frequently lie down on the line of rails under the rope, so that when the rope is started it may awake them by its motion, but at times so sound is their sleep, that it has failed to rouse them in time, and a train of coal waggons has passed over them, causing in most cases death.
The coal having been brought to the pit-mouth, it remains to be shown what becomes of this most valuable mineral, the consumption of which is now so large in all parts of the globe. The next person employed in the trade is the sailor, to convey it to the market, and the collier vessels are a valuable navy to the country, proving quite a nursery of seamen for our royal marine service. Newcastle, Sunderland, West Hartlepool, and a large number of other ports along our coast, have an immense amount of shipping employed exclusively in the coal trade—no less than 5359 vessels carrying coal having entered the port of London alone in 1873, and the average annual quantity of coal exported abroad during the three years ending 1872 was 12,000,000 tons.
I will not now detain you longer on the subject of the extent and working of coal, lest I should tire your patience; but before concluding I should wish to give some account of the uses to which this most valuable product is applied. The main use of coal, as we all know, is to produce heat, without which many a paterfamilias would grumble when the dinner-hour came and he had nothing hot to eat. It not only, however, supplies heat, but the beauty of the processes for lighting up our houses is now mainly derived from coal. The immense consumption of coal, among other things, is in the production of the vapour of water—steam, by which our thousands of engines on sea and land are made to perform their various appointed tasks. This production, formed of decayed vegetable matter, which in ages past nourished on the surface of the earth, as I have already shown, is again brought forth for our use, and is a testimony of the goodness and kindness of God in providing for our wants. By its heat some 10,000 locomotive engines are propelled, and many hundreds of iron furnaces are kept in work, besides those for other purposes. It moves the machinery of at least 3000 factories, 2500 steam vessels, besides numerous smaller craft, and I cannot tell how many forges and fires. It aids in producing delicacies out of season in our hothouses. It lights our houses and streets with gas, the cheapest and best of all lights—London alone in this way spending about £50,000 a year. It gives us oil and tar to lubricate machinery and preserve timber and iron; and last, not least, by the aid of chemistry it is made to produce many beautiful dyes, such as magenta and mauve, and also, in the same way, gives perfumes resembling cloves, almonds, and spices.
The annual consumption of coal in Great Britain is reckoned to be not less than 80,000,000 tons. The amount raised in 1873 amounted to 127,000,000 tons, and of this was imported into London alone 7,883,138 tons—4,000,000 tons, or 15 per cent. of the total out-put of the country, being sent from Durham alone. The cost of the Wallsend coal on board the ship may be stated at 10s. 6d. per ton; to this must be added the charge at coal-market of 2s. 8d., freight say 5s. 9d., profit 7s. 6d., so that a ton of coal of this kind will cost in your cellar in London the sum of £1, 6s. 5d.
I think it is now time to conclude this most interesting subject, for though I have by no means exhausted it, yet I fear I have said as much as a lecture will warrant. The subject shows us how mindful a kind Providence has been of man, and to this nation in particular, for to our coal we in a measure owe much of our greatness. So while we admire the geology of our globe, let us not forget who made it and all that it contains, and who, when He had finished the work, pronounced it all very good. Let us so strive to live, that though we may be called away suddenly, as 199 of our fellow-creatures were called by what is termed a mining accident, we may be ready to meet Him who not only made us, but made the coal, and who, when man, at first made perfect, fell away, was pleased to send a Saviour to redeem us and bring us to that light which fadeth not away.