Professor of Physiography and Astronomy, City of London College; Lecturer on Geology, Crystal Palace School of Engineering; Vice-President of the City of London College of Science Society; Member of the General Committee of the British Association; Member of the Geologists' Association; Hon. Member Hamp. F. C., etc. Author of "The Study of Geology," Geology for All," "Mount Vesuvius,” Hampstead Hill," "The Inter-relations of the Field Naturalist's Knowledge,”; "The Cretaceous Rocks of England," "The Causes of Volcanic Action," "The Origin of Gold," etc. 66 ALTHOUGH England was prosperous when our great supplies of coal were unknown, the population was then so much smaller than now that the produce of the land as merely agricultural land fully sufficed for the support and welfare of the people. The immensely increased population of the present day requires other wealthproducing agencies than agriculture, and it is not too much to say that the foundation of the modern power and wealth of Great Britain is the coal of British rocks. For, however much may be due to the energy and skill of the people, England, without her abundant coal supply, would have been also without her principal manufacturing industries, and consequently lacking in the great wealth-creating agencies as it now exists. The abundance of coal in the rocks of these small islands is so great that in 1871, after the enormous consumption and exportation that has been going on for centuries, the Royal Commission on our coal supply in that year estimated the amount of coal still untouched at 146,480,000,000 of tons. And not only is coal abundant in the British Islands. but it has a wide distribution also, and so adds to the value of land in many localities, for coal is to be obtained from the rocks of all of the following counties :-Anglesea, Antrim, Argyleshire, Ayrshire, Carmarthenshire, Carlow, Cheshire, Clackmannanshire, Clare, Cork, Cumberland, Denbighshire, Derbyshire, Dumbartonshire, Dumfries-shire, Durham, Fifeshire, Flintshire, Glamorganshire, Gloucestershire, Haddingtonshire, Inverness-shire, Kilkenny, Lanarkshire, Lancashire, Leicestershire, Leitrim, Limerick, Mid-Lothian, Monmouthshire, Northumberland, Nottinghamshire, Pembrokeshire, Queen's County, Renfrewshire, Shropshire, Staffordshire, Stirlingshire, Somersetshire, Tipperary, Tyrone, Warwickshire, Worcestershire and Yorkshire. This long list of no less than forty-four counties indicates only the known coal-fields, but as Professor Hull remarks, "It is unquestionable that very large quantities lie concealed beneath Permian, Triassic and even Liassic strata beyond the margins of these coalfields themselves." The recent striking of a seam of good coal by Sir Edward Watkins' boring at Dover indeed will conclusively show to those quite unacquainted with geology that new coal-fields may yet be established in England, if not in the other parts of the British Islands. It would be out of place here to give the reasons for the belief entertained by geologists in the existence of workable beds of coal in the south of England, but it may perhaps be stated that coal has already been proved along two-thirds of a line extending from Westphalia to Pembrokeshire in South Wales, and that the part of the line where coal is not yet obtained passes through the counties of Kent, Surrey, Berks and Wilts. Since Dover is on this line, and the occurrence of coal there is in entire accordance with the views held by geologists for nearly half a century, it is probable that other borings. at points, recommended by those who have given special attention to the subject, will soon be undertaken. All the coal of the British Islands now worked is in the Carboniferous Rocks which underlie the Permian, the uppermost of the Paleozoic division of the sedimentary rocks. In some localities coal is worked below the Permian, as in Durham, where the mines are consequently deep, but in others the coal seams crop out at the surface, as in the South Yorkshire, the Lancashire and the Shropshire coal-fields, and can be worked, in some cases, by galleries from the hill sides without shafts. It is considered, however, that good seams of coal may be profitably worked as deep as at four thousand feet from the surface. Coal is a hydrocarbon containing usually about eighty-three per cent. of carbon, six of hydrogen, and eleven of oxygen, and being the result of the mineralisation of vegetable matter by the elimination of some of its hydrogen, and much of its oxygen, may be found in various formations. Indeed, from 1814 to 1827 the large quantity of seventy million tons of coal was obtained from the Lower Oolites of Brora in Sutherlandshire, but this coal-field was abandoned in 1832. The conditions, however, most favourable for the production of coal appear to have existed chiefly in the Carboniferous period, and therefore it is only, as a rule, looked for in localities where the uppermost division of the Carboniferous rocks, called the Coal Measures, or the succeeding 798 LAND ITS ATTRACTIONS AND RICHES. Permians form the surface. But as is strikingly shown by the Radstock coal-field in Somersetshire, coal may exist at workable depths below much newer rocks, since it is there successfully worked below the Lias as the surface rock. It must not, however, be expected at any locality where older rocks than the Carboniferous are seen at the surface. A remarkable case of the occurrence of coal in an abnormal position is seen at the Clee Hills in Shropshire, where the Coal Measures are found at seventeen hundred and eighty feet above the level of the sea, and under a mass of basalt, or old volcanic rock, forming the summit of the hills, which, indeed, from its great hardness, has resisted the wearing action of denudation, and so has secured these hills from destruction, and has actually preserved the coal, above which it flowed as lava, through vast ages for the use of man. J. LOGAN LObley. |