Our Coal Resources — The Deepest Mine
Professor Morris describes the carboniferous series of rocks in England which contain Coal as deposited above the old red sandstone, or what have been called the Devonian rocks, and several thousand feet in thickness, though the coal measures are of much more limited depth, and the mines of coal vary from thirty feet to only two inches thick. The distribution of Coal in England is much greater than in any country in Europe; though in the United States of America, near Pittsburg, the beds of coal extend over a vast area, and one is of great thickness. The quantity of coal that is raised from the pits in this country, however, exceeds that from all the other coal-fields in the world.14 The probable duration of coal in England has formed an interesting subject of speculation with some geologists, who have estimated the period variously at from 300 to 1000 years. Sir William Armstrong, at the Meeting of the British Association, in 1863, estimated the minimum period of the northern coal-field at 200 years; but Mr. N. Wood, the great coal-viewer of the North, is of opinion that of the northern coal-field no conjecture, of practical utility, can yet be formed, as more than one half of the basin, lying under the sea, has not yet been explored.
Sir William Armstrong’s remark, however, was misunderstood, and thought to refer to the coal supply of the whole kingdom, whereas he limited the remark to the coal-field of Durham and Northumberland. This misapprehension re-opened the question of the exhaustion of our coal resources, and led to the communication of some valuable evidence to the Times journal. Thus, Mr. E. Hull, of the Geological Survey, states as the result of a series of investigations of the British coal-fields, that adopting the limit of depth at 4000 feet, he found there to be enough workable coal, at the rate of consumption for that year, (about 71,000,000 tons,) for nearly 1000 years; and even if the consumption should ultimately reach 100,000,000 of tons, that supply could be maintained for 700 or 800 years.
With respect to the assumed depth, 4000 feet, Mr. Hull adds:
“Already a depth of nearly 1000 yards has been reached in a Belgian colliery, and coal is now being extracted from depths of 700 and 800 yards in Lancashire. Even with the vertical limit of 4000 feet, I have since found reason to believe that the estimate I arrived at in the case of the South Wales coal-field was rather under than over the truth. In that coal-basin alone, with an area of 906 square miles, I calculated that the rate of consumption for 1859, of 9½ millions of tons, could be maintained for 1600 years; but it is only right to state, that Mr. H. Vivian, M.P., in a pamphlet published by him in 1861, controverts this view, and arrives at the conclusion that ‘South Wales could supply all England with coal for 500 years, and her own consumption for 5000.’
“As regards the absolute quantity of mineral fuel in this island, it may be considered as practically inexhaustible. The seams of coal outcrop in our coal-fields, and descend under the Permian and Triassic formations to depths exceeding 10,000 feet. The question of the available supply is therefore one depending on the rapidity of production and the limit of depth.”
Dr. Buckland, in 1841, dwelt upon the wanton waste of coal at the pits, which, in 1836, he had maintained would finally “exhaust the Newcastle coal-field at a period earlier by at least one-third than that to which it would last if wisely economized.” The waste has, however, been much abated.
Mr. Robert Hunt, however, maintains the consumption to be greatly understated. He says:
“All calculations on the probable duration of our coal-fields have been founded on the very erroneous data which supposes that not more than 36,000,000 of coals are raised annually. We know that more than sixty-six millions of coals are now annually produced, and the demands upon our resources are rapidly increasing.”
Sir William Amstrong himself quotes Mr. Hunt as showing “that at the end of 1861 the quantity of coal raised in the United Kingdom had reached the enormous total of eighty-six millions of tons, and that the average annual increase of the eight preceding years amounted to 2¾ millions of tons.”
If, therefore, Dr. Buckland’s remarks were important in 1836 (when his Bridgewater Treatise was first published), and of “greater force” in 1858, how much more must they be worthy of most serious consideration in 1863.—Communication to the Times by Mr. Frank Buckland. Another Correspondent, however, adds this consolation:
“There may yet remain plenty of coal in the world. Three-fourths of the globe are covered with water, and what geologist shall presume to declare that there are no vast deposits of coal deep below the ocean bed? We have been up and down below the waters several times, and we shall probably sink again; but then the bed of the Atlantic may become dry land and peopled with our successors. Change is the law of the universe. The moon is stated to be approximating to the earth at the rate of a fraction of an inch in a century or so, and may one day come tumbling upon us. The whole of the solar system seems to be travelling—some report at the slow rate of 47,000 miles an hour—towards an unknown region of infinite space. Great Britain, therefore, has no reason to complain if she shares the common fate of all things, whether in the heavens above or on the earth beneath.”
Monkwearmouth, Sunderland, is the deepest coal-mine in all England; the coal being won at nearly two miles’ distance from the shaft, and upwards of 1900 feet, or more than five times the height of St. Paul’s, below the surface of the green fields and trees above. The pit employs nearly 300 hands, and yields between 500 and 600 tons of domestic coal per day; every few seconds, the tall cage shoots up out of the gloom of the shaft, and the tubs, like miniature railway-waggons, holding nearly half a ton each, are brought to the bank, and wheeled away in different directions. Not for a single instant does the work stop: it is coal—coal everywhere beneath and around; the very atmosphere is made gloomy with its fine particles; and all this, seen amid clanking of chains, roaring of steam, and the rapid activity and whirl of hurried business, make it one of the most curious and interesting scenes imaginable.
The dangers of the working are thus detailed. The boys in charge of the trams carry the “Davy,” the wire-gauze of which is far less liable to injury than the glass shade of the “Geordie,” or Stephenson lamp; and with these the lads may safely pass the “goafs” or worked-out seams, in which, though built up as far as possible, gas always lurks, though the invisible enemy around them is so thick that the gas will light inside their lamps and burn with a ghastly blue flame. Beyond this steep incline or bank there is still nearly a mile to be traversed to the “in-bye”—the face of the working, the spot from which the coals are actually won: where, too, the gas has its head-quarters, and has to be watched and guarded against every hour and minute of the day and night, for the work of a mine never stops, and day and night are meaningless terms in such eternal gloom and silence. The heat at the bottom of the bank, indeed in all parts of the mine, is very great in the extreme depths of Monkwearmouth. It is seldom less than 84 or 85 deg., and at the workings often over 90 deg. So great is the heat, in fact, that the men nearly always work almost naked, and in some cases absolutely so. The heat certainly does not arise from want of proper ventilation, which seems ample. Not much bratticing is used to convey the air through the workings, and it is almost entirely confined to the places where the coal is won. In fact, as far as human ingenuity, skill, or experience can go, the pit is made safe from gas at least. Its only risk seems to be from shaft accidents or inundation, to both of which more or less all colleries in this district and near to the sea are, to say the least, equally exposed and equally protected against, as far as it is possible to do it.