sumption of coal in iron smelting would have been, in It must not however be concluded that this enormous development in the Scotch trade was due to the hot blast alone. Concurrent with that great improvement was the employment of the abundant and economical mixture, the "blackband," for the discovery of which Britain is indebted to Mr. Mushet. But the main fact remains that every advance which tends to cheapen the productions of manufacture enlarges so widely the field of operations, that coal, the basis of the whole of them, is always demanded in ever-increasing quantity. In the absence of accurate data it is estimated that in Great Britain about ten millions of tons of coal were raised in a year at the beginning of this century. The continental production at the time was exceedingly small, the backwardness of many manufactures and the large expanses of forest land having delayed the necessity for turning to subterranean fuel. Within a short time after the conclusion of the great war, steamengines were rapidly supplanting or acting as auxiliaries to water power, and the coalfields of our own and foreign districts became the scene of more active researches. But it was not until the facilitation of traffic by means of steamboats and railroads, that the steady, absorbing march of the present epoch commenced. When between 1829 and 1835, the locomotive engines running on wrought-iron lines, and the coasting and sea-going steamers, were proved to be a triumphant success, leading to imitation in foreign countries, and to enormous multiplication in our own, a new system of the distribution of raw material may almost be said to have been started. Nowhere is the result more striking than in the London district, which now receives by sea, railway, and canal, upwards of five millions of tons per annum, or doubtless more than the production of the entire kingdom in the earlier years of George III. Many new and striking applications of coal have within the last few years rewarded the exertions of chemists. The once useless and fetid products of its distillation have been made to yield sweet scents and savours. From its naphtha are obtained the paraffine oil and the beautiful translucent solid paraffine, which in brilliancy and purity excels wax itself; and from its aniline are obtained a galaxy of brilliant colours, among which need only be mentioned the popular mauve and magenta to prove the varied forms under which the products of coal have found their way into the useful arts. The International Exhibition of 1851, possible only under these conditions of mechanical advancement to which we have referred, naturally directed the attention of inquirers more forcibly to the statistics of mineral produce. It was roughly estimated that for 1850 the production of all the British coal-mines was 42,000,000 tons; France was raising 4,433,000 tons; Prussia and Belgium followed, with smaller quantities; and then Austria, with a little above 1,000,000 tons. In 1853, Mr. T. Y. Hall, of Newcastle, after much investigation, stated the British production to be 56,550,000 tons. At length, in 1854, through the instrumentality of Mr. Robert Hunt, of the Government Mining Record Office, aided by the recently appointed inspectors of coal-mines, we obtain reliable statistics; and the following table will command the attention, if it does not excite the astonishment, of every reader. The vast quantity represented by these figures may be brought before the eye by the following comparisons, supposing that we take the approximation of one ton being, as it lies densely packed in the earth, one cubic yard. If we 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 in 1865 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 * The exports of 1854 to 1858 are from the returns to the House of Commons, the remaining numbers are taken from the statistics compiled by Mr. Robert Hunt, F.R.S., Mining Record Office, Museum of Practical Geology. 1870, 110,431,192 tons (coal produced), 11,487,878 tons (coal and coke exported). feet thick and ninety-nine feet high; whilst if put together in the broken state in which coal is commonly used, it would give a wall of more than double that thickness. This yearly production, obtained by the labour of about 240,000 men, is palpably a gigantic effort for so small an area as that of our united coalfields, and naturally excites apprehension for the future. The statistics of the produce of the mines of most of the European nations are well kept up, although a few of them can only be roughly estimated, and it is interesting to compare the ANNUAL AMOUNT PRODUCED BY THE CHIEF COAL-BEARING COUNTRIES. It is hence evident that although our favoured country has so long taken the lead, all civilised countries have entered into the race of competition; and it becomes a matter of anxious inquiry to learn under what circumstances the treasure is in each country developed, and where it is likely to be best expended or longest economised. * Given in the official statistics in zollcentner, of which 20 early. + The Vienna centner is 56 kilogrammes, the zollcentner 50. Report of Chief Commissioner of Mines, Halifax, 1872. = 1 ton CHAPTER II. MODE OF OCCURRENCE OF COAL THE substance receiving the name of true coal (in contradistinction to lignite and brown coal) is, in almost all the coal-producing countries, found in beds or seams divided from one another by more or less thick strata or beds of shale, sandstone or grit, and indurated clay, the whole being termed collectively the Coal Measures, and belonging to a still larger group of stratified rocks called the Carboniferous Formation or System (Systême houillière, or anthraxifère, Fr.-Steinkohlen-gebirge, Ger.). It is difficult to define exactly what constitutes a Coal. Several legal trials on a grand scale, in Edinburgh, London, and in Prussia, have only succeeded in making it more clear than ever that no suitable definition exists, and that whilst all parties may agree in recognising the characters of a typical coal, differences of opinion will soon arise when the substance to be determined approaches the boundary of the shales and of the bitumens. It is obviously loose to assert that "anything is a coal which is dug out of the earth and will burn; whilst on the other hand it is inconveniently strict to demand any approach to a definite composition as indispensable to coal. We may fairly require of it that it be black or dark brown, capable of direct employment in furnaces and fire-places for the production of heat, brittle, and not soluble-like the bitumens-in ether, oil of turpentine, or benzole. The |