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GASES FOUND IN COAL MINES, AND ON
E. W. BINNEY, ESQ., F.R.S., F.G.S.,
PRESIDENT OF THE MANCHESTER GEOLOGICAL SOCIETY.
[The author of this practical and able lecture on Mining Lamps
and Explosire Gases, is well known throughout the scienti. fic world as an eminent geologist and mineralogist. We feel mach indebted to Mr. Binney for the permission to publish his original and valuable lecture, which we hope will be circulated as widely as possible by colliery owners, and other persons who are interested in the safe working of our extensive and inestimable coal mines. It is a hopeful sign that a College of Practical Mining is about to be established at Newcastle-on-Tyne, under the auspices of the North of England Institute of Mining Engineers, and with the general support of the coal owners of Northumberland and Durham. Such an institution must prove a national blessing, by its promotion of skill and economy in the getting ivi coal, and the security of life and property. The Duke of Northumberland, who is patron of the College, has promised £10,000 as soon as £30,000 have been raised for its endowment.)
As I have on several occasions publicly advocated the desirability of plain lectures being delivered to the officers of collieries, and working colliers, on the origin and properties of fire damp, and the construction of mining lamps; and finding that no one has been induced to take up the subject, I am led to do it myself, although I am well aware that I am by no Te-as fitted for the task I have undertaken. Some years since the late Mr. Francis Looney, F.G.S., a gentleman well known for the interest he took in the education of the working classes, having been provided with mining lamps by the Manchester Geological Society, went round at his own expense and delivered lectures to the colliers of the different districts in Lancashire. Mr. Looney having presented these lamps to me, I feel in some measure bound to follow his example, and revive the subject until the useful nature of it is better known, and abler lecturers are induced to take the matter up.
Coal is a substance well known to most people; and it is hard to believe that disputes should have arisen, and thousands of pounds been spent in order to determine whether a body was or was not coal
. Yet this has taken place in our day. If a man found a seam of black substance in the earth, and it bunt like coal, and made gas like coal, he would naturally conclude that it was coal, and call it as such, without sending it up to the chemists, geologists, mineralogists, and microscopists of London, to ask their opinions. These learned gentlemen might find fault with its colour in being brown and not black. Some might day that it had too much gas, and others too little gas, for the coals they had been accustomed to sce. Others might again say that it contained too little ash, or too much ash, for their ideas of coal. Probably it will be as well to take Dr. Redfora's definition, who says :-"Under the term coal, those substances must be comprised which consist of compressed and chemically altered vegetable matter, associated with more or less of earthy substances
, and capable of being used as fuel."* À Lancashire man who had been accustomed to see the bright pitchy looking cannel of Wigan, would hardly include under the term cannel the brown earthy-look ing parrots of Scotland; whilst a Newcastle man world scarcely recognise the blazing Wallsend coal with the smouldering anthracite of South Wales. Yet in each district the substances would be well known as coals, and no doubts would be entertained as to their nature. As coal ought not in strict language to be calleda mineral (which includes only brute and not organic matter, however altered), the opinion of common people on the productions” of their respective districts
* Quarterly Journal of Microscopical Science, VOL. lii., p. 906.
, is entitled to some respect, and they certainly have as much right as a stranger to give it a name. About one thing, however, there is no doubt, namely, that coal is of vegetable origin, and consists of the remains of plants. There is certainly a considerable difference between a piece of wood and a piece of coal
, but not more so than between a piece of liquorice root and a lump of Spanish juice; both are equally of vegetable origin, however much they are wow changed in appearance. The chemist tells you that coal is of vegetable origin by its composition; the geologist shows you the floor of the coal, a rich silty clay, full of countless roots, and the roof studded with upright stems of plants, well known amongst colliers as potholes, whilst the coal itself is and brasses found in coals, and proves them to be 1958; and the microscopist cuts the hard nodules samples of the old vegetables preserved and her. metically sealed up, and now showing the minutest seeds and vessels. The nature of the plants, of which coal has been formed, is not yet well known, but the most eminent living botanists are decidedly of opinion that they were aquatic; and from the fact of most deep seams of coal now containing salt water, it is pretty clear that such plants once grew in sea water, even if the remains of the fishes and shells found in the adjoining strata did
a marine origin, which they most In the Lancashire coal field, from the bottom to the top, there must be at least 120 seams of coal, great and small.
These indicate 120 periods of
not indicate decidedly do.
rest or repose of the earth's crust, when a primeval forest reared its top above the waters until the vegetable matter now forming each bed of coal was grown and deposited. Then such forest was submerged and buried under mud and sand, now found as shale and sandstone rocks. The hollow caused by such subsidence is silted up until it is again covered over by shallow water. Then again a fresh crop of vegetation flourishes, so as to form another bed of coal. For 120 times does this successive growth of vegetable matter, submergence, and silting up go on. In some instances, whole forests of Sigillaria, standing upright in fine shale, on the top of the seams of coal, are met with, thus clearly showing that they were submerged quietly and slowly; whilst at other times the prostrate stems now found lying in sandstone, and other roots, show that the submergence was rapid, causing strong currents, that tore up and drifted the trees. All the floors of coal seams are full of the roots of Sigillaria (Stigmariæ); so with the stems of trees in the roof, vegetable matter in the seam of coal, and roots in the floor: there can scarcely exist a doubt, therefore, as to the remains of the vegetables now composing coal having grown on the spot where it is now found, and that stigmaria was the characteristic root of the plant, which for the most part produced coal.
The constituents of the gaseous mixtures given off by coals when compared with the known composition of wood and coal, enable us to form a very probable conjecture respecting the mode of their formation. It is now admitted that coal is the product of the gradual decomposition of wood, by 3 kind of mouldering process in the presence of water, pressure, and a limited supply of air. These agencies have all had a share in the transformation; but we are unable to trace the influence which each may have separately exerted towards the ultimate result.
If we dedact from the elements of wood ..
We obtain the elements of splint coal
24 13 0* The whole of the coal fields of Great Britain are disjointed and fractured portions of one great field, and although the true foundation of our national greatness, and larger than any other yet discovered in Europe, are of small extent when compared with the enormous coal fields of the United States, which in extent probably exceed all those of Europe put together. The exact areas of the different coal fields, and how much coal they are likely to produce, it is difficult to state with any degree of precision, 28 Do one yet can tell how far the seams of coal may be worked under their overlying deposits.
There has lately been published by Government in the report of the inspectors of coal mines, a summary of the production of coal during the last year (1857), with the number of lives lost. As it contains much information in a small compass, I shall give it entire. It is as follows:- During the
year 1857 there have been 74 explosions of fire damp, 360 accidents from falls of roof, coal, and sides of workings, 144 in shafts, miscellaneous 182, making a total of 760 accidents: of these there have been 377 lives lost by explosion, 372 by falls, 162 in shafts, and 208 miscellaneous, making a total of 1,119 lives lost. During the year 1856 there were about 230,000 persons employed in and about the collieries of Great Britain, and about 661 million tons of coal raised. The loss of life by accidents was, therefore, at the rate of aboutone person killed in each 224 employed, and one killed for each 64,751 tons of coal raised. In the year 1857 the production of coal was consider
Ronald's and Richardson's Chemical Technology, Vol. 1, Part 2, p. 514.