COAL AND COAL-ALINING.*
Mn. WARINGTON Su= has very aptly supplied a distinct want that has been felt in the literature of the practical arts. He fur- nishes us with a clear and interesting account of all that concerns the winning and working of coal. He is neither so technical, on the one hand, as to drive away all but professional readers, nor is he, on the other hand, in the least too popular and superficial. And a work of this character was undoubtedly wanted, because the coal-mining industry of this country is year by year assuming a position of increasing predominance. The quantity of coal actually raised in 1865 was almost one hundred millions of tons (more exactly, 98,150,587 tons), and the value of this quantity at the colliery was 24,537,6461., whereas the value of all the other minerals raised was only 7,821,4591., and the value of all the metals produced from them was only 15,773,2871.
This growing predominance of our coal-mining and manufactur- ing industry has been marked within the last year or two by an event of singular historical interest, namely, the collapse of Cornish mining. The celebrated Parys Mine, in Anglesey, after a brilliant career, has for some time subsided into obscurity. Our lead mines have probably seen their brightest days ; our manga- nese mines long since succumbed to foreign competition. Borrow- dale cannot long supply the world with the best graphite. But the failure of the Cornish Mines has come upon us suddenly and unexpectedly. It is the failure of England's first staple product. In the earliest obscure reference to Britain which we meet in history, these islands were called the Cassiterides, or Tin Islands. The Phoenicians, there is no doubt, habitually visited the Scilly Islands and Cornwall for the purpose of getting tin, but they pre- served the knowledge of the position and character of this country as a valuable trade secret.
From that time to the present the Cornish Mines have formed one of the chief staple industries of Britain. The tin and copper there gained have been invaluable to the metal-working trades of Birmingham ; the arts of mining were there cultivated in the highest perfection, and what is more important, the steam- engine was there brought into successful use. Savary, Murdock, Trevethick, Woolf, and others, who have contributed to the per- fection of the engine, were men engaged in Cornish mining. In Cornwall, too, Bolton and Watt found the first profitable field for the erection of their improved engines. There they esta- blished the system of recording and reporting the performance of engines which caused such beneficial emulation. But now these days seem near their end. The Cornish engines, according to the latest reports, have fallen back iu their performance, and the mines have to a great extent been abandoned. A month ago, as we were informed by a gentleman engaged in investigating the state of the mines, there were but 300 mines in work out of GOO that were working a few years since, and only 20 mines paid any dividend last year. About 5,000 miners have in consequence been obliged to emigrate, chiefly to other parts of England, especially to the coal-fields. To what must we attribute this sad result? Partly to the pro- gressive exhaustion of the mines no doubt, but chiefly to the progress of free trade and the competition of other industries. It is attributed commonly to the present low price of tin, which has been about 901. per ton for the last year. But this taken alone does not explain the collapse, because the price used fre- quently to be less than 901. Between 1817 and 1851 it was seldom long above 901., and in 1843 fell as low as 601. per ton. Either we must allow that the rise in the cost of materials and commodities in general has been very considerable, or we must attribute the failure to an intrinsic exhaustion of the Cornish Mines. We are more inclined to look to extrinsic causes. Our vast exports of manufactures enable us to buy up ores and raw materials in all parts of the world. The trades which smelt the ores and the trades which use the metals when smelted, so far from showing any tendency to collapse, are rapidly progressive. It is an apparent paradox that, when we want more and more tin and copper our own mines should have to be abandoned, but this only of a piece with the general change going on in our industries. It is the increasing predominance of our coal-mining interests, and all the industries which depend upon the profuse consumption of coal, which overshadows and over- competes with our other trades. This process is marked and completed by the migration towards the coal-fields which is going on in Great Britain. Had the Cornish miners no resource but to stay in Cornwall, they must have accepted the lowest possible wages that would keep them alive, and the mines might by
. d Treatise on Coal and Coal-Mining. Watington W. Smyth, ILL, MS., em. London : Virtue. 1867. cheap labour have been soon started again. But the coal- miners offer temptingly high wages, and the coal-mine pro- prietors are but too glad to get a new supply of trained miners. The absorption of the superfluous Cornish population by the coal districts is a happy thing for them and the country at large, but by keeping up wages and withdrawing labour from the. mines in Cornwall it must be fatal to the latter. This transference, after all, is but analogous to that of agricultural labourers into districts, which a certain public-spirited country clergyman has lately been promoting.
Mr. Smyth has well pointed out the enormous dimensions which. the Coal Trade of Great Britain has already attained. He thus. illustrates the amount raised in 1865:— "If wo take the area of Lincoln's Inn Fields, measured up close to the. houses, at eleven acres, about the dimensions of the base of the Great.
Pyramid, and could stack the coal as nature has done in the seams, the British coal raised last year would form, on that base, a solid block of the height of 5,229 feet. or as high as Snowdon surmounted by another mountain of half its height. Again, taking the distance from London to Edinburgh, four hundred miles, the same quantity, similarly packed,. would build a wall the whole way of twelve feet thick and ninety-nine feet high, whilst if put together in the broken state in which coal is com- monly used, it would give a wall of more than double that thickness._ This yearly production, obtained by the labour of 240,000 men, is pal- pably a gigantic effort for so small an area as that of our united coal- fields, and naturally excites apprehension for the future."
To add another comparison to those of Mr. Smyth, we may take the cubic volume of the coal raised in 1865 as just about 100,000,000 cubic yards. The solid content of the Great Pyramid of Cheops is found to be 3,394,307 cubic 'yards. We therefore raise yearly an amount of coal thirty times as great in bulk as the Great Pyramid. This quantity, too, is raised from the bottom of our mines by 240,000 men working one year. The Great Pyramid, as we are assured by Herodotus, required the united labours of 100,000 men during 20 years, which is equal to the labour of 2,000,000 men during one year. A simple calculation will show that in our coal-mining each man on an average raises 250 times as much material in a year as each of the ancient Egyp- tians engaged on the Pyramid. We need hardly point out, how- ever, how very unfair this comparison is to the ancient Egyptians. in some points.
After describing the mode in which coal appears to have been produced in former geological ages, and the chief characteristics. of the coal-fields now known, Mr. Smyth proceeds to describe the most improved processes of coal-mining. A considerable interest. attaches to the subject of boring, as it will in time become necessary to explore by this means some of the more deeply lying coal-beds. It is stated that on the coal-field of Creusot, in France,. a bore-hole has lately been sunk by Herr Kind to the depth of 3,017 feet ; shafts, too, as wide as from 3 to 15 feet in diameter have been made in Westphalia by a gigantic boring apparatus.. The use of powerful steam-engines for working the boring rods,. and the injection of streams of water to bring up the debris of the rock cut off by the boring tool, offer a prospect of sinking to great. depths.
Ordinary shafts are, however, still sunk by the miner's pick, the hammer and wedges, or by blasting with gunpowder. No. advance has bean made in this respect since the introduction of gunpowder, nor are we aware that any apparatus for boring the blasting holes, like that in the Mont Cenis Tunnel, has been tried- The one great difficulty, however, which the mining engineer fears in sinking is the irruption of water ; a quicksand, or bed of loose, wet sand a few yards thick may be almost impenetrable,. and has before now stopped the sinking of a pit altogether. A French engineer, M. Triger, introduced in 1845 the ingenious. device of closing the shaft and filling it with compressed air, so as to keep the water out of the pit, or else cause it to flow easily to the surface through an upright pipe. He found that men could work in air under a pressure of 8 atmospheres, which enabled him to overcome any feeders of water to a depth of about eighty feet, but the device is obviously inapplicable to feeders of water at a greater depth. In England the only resource against over- whelming streams of water has been powerful pumps, and then tubbing. As water is seldom met with in the deeper parts of of coal-mines, it would obviously be absurd to let the water from the higher parts of the shafts fall to the bottom, thence to be pumped out at great cost. The water is, therefore, either collected at the point where it is met in cisterns, and pumped thence to the surface, or it is tubbed out by a water-tight casing of iron plates, carried completely through the water-bearing strata, and fitted tightly into the dry rocks above and below. The shaft, in short, is carried through an iron tube, and however great the cost of this tube may be at first, it is far more economical than the
continuous pumping that would otherwise be necessary. At the Shire Oaks Colliery, completed in 1858, " heavy feeders of water, which during the sinking yielded as much as 500 gallons, or 2f tons, of water per minute in the two pits, have been thoroughly excluded."
The modes of working the coal by post and stalror by long-wall work, the winding apparatus, the ventilation by furnace or by mechanical pumps, and all the minutiae of coal-mining are described in a thoroughly satisfactory manner, so that from Mr. Smyth's little work the professional colliery viewer will be sure to learn more of the theory of mining than he knew before, and the public will learn much of the practice. Too much attention cannot be paid to anything that will render our mining more successful or . safe. For while it is imperative upon us to increase the depth and extent of the workings of our mines, to meet the growing demand and keep the price of our staple product down, we incur an increasing liability to dreadful accidents like that at the Oaks Colliery last year.
Mr. Smyth's volume is completed by some remarks on the dura- tion of the British coal-fields, which seem to be very judicious and moderate. While he thinks we can sink to much greater depths than have yet been attempted, he speaks with natural disgust of the millions of tons which are now being wasted annually by being buried in gobs, stowage, crushed pillars, &c. It is hardly likely that even the Coal Commission will be able to suggest any mode of saving all the present loss, but the Commissioners can, we should hope, obtain an alteration of the incredibly foolish law which obliges colliery owners to provide plans of their workings while in progress, but allows them to be destroyed when the • colliery is laid in. While we have a Mining Record Office, estab- lished to receive such plans, we allow them to be lost or destroyed, -and thus throw, for no purpose whatever, immense difficulties in the way of reworking tracts of country when there will be a greater need of coal than at present.
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