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admission of these causes when the general tenor and evidence of the phenomena naturally suggest them, as it would be to introduce them gratuitously unsupported by such evidence. We may surely, therefore, feel ourselves authorised to view, in the geological arrangement above described, a system of wise and benevolent contrivances prospectively subsidiary to the wants and comforts of the future inhabitants of the globe, and extending itself onwards, from its first formation through all the subsequent revolutions and convulsions that have affected the surface of our planet."

CHAPTER IX.

BORING AND SINKING.

Relative Views of the Miner and the Geologist in searching for Coal-Extent and localities of carboniferous strata mostly ascertained-Superficial indications of Coal-Examination by boringDescription of boring apparatus—Interesting nature of the search after mineral treasures-Sizes of pits Windlass used in commencement of sinkingWalling inside the shaft-Tubbing-Blasting with gunpowder-Description of the horse gin-Expensiveness of sinking deep pits-Pemberton's shaft at Monkwearmouth-Adits or drifts.

HAVING disposed of the Natural History and geological relations of coal, we now come to treat of its obtainment by means of human industry. However attractive coal might have been or may be considered, as a mere fossil, to scientific enquirers into the nature and formation of the earth, it is mainly to considerations connected with its importance as the most valuable species of fuel, that we owe our so large and generally accurate acquaintance with its properties and situation. For, let the zeal of the geologist be what it may in pushing scientific inves

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tigations over various countries to a great extent, or to whatever depths in the earth on a given spot, the practical self-interest of the collier will rarely fail to surpass it in exploring any locality where coal is likely to be found. These parties, indeed, are not commonly found proceeding in concert, at least, the latter has only been induced of late years to defer to the former in reference to strictly untried ground; and perhaps the advantages which would arise from the working of thick seams of good coal, sufficiently account for the many unsuccessful attempts to discover them. "The opinions of working colliers on this point," observes Mr. Phillips,* "have too often been preferred to the legitimate deductions of science; and even yet persons will perhaps be found willing to credit the delusive tale of finding good coal by going deeper."

Formerly, the absurd and arbitrary notion that coal might be found any where in this Island by only sinking deep enough, prevailed to a considerable extent. Men of the present generation residing in or about London, may have heard their grandmothers gravely assert that coal might be raised from under Blackheath, and other equally unlikely places, were it not that Government did not allow the search lest the discovery might interfere with that "nursery for seamen," the coast coal trade! It is allowed by experienced geologists, that workable coal may hereafter be discovered in some new situations or at great depths; as, for instance, covered by magnesian limestone or red sandstone, or beneath the lias, as the coal measures of Durham and Western Yorkshire, appear in some instances to run under these subGeology of Yorkshire, p. 182.

stances; but this is very uncertain. Indeed, within the last thirty years, there has been disseminated such accurate and extended knowledge of the state of the coal districts, and of the associated strata of the island generally, as to render it much less probable that unknown seams exist to any great amount, than might have been supposed at an antecedent period. Before the publication of the geological map of England by Mr. Smith, and of another by Mr. Greenhough, to say nothing of various local surveys, there existed hardly any general information on this subject; and an opinion, as already stated, prevailed, that coal might be found, at certain depths, almost as certainly in one county as in another. But the experience of scientific observers, as Dr. Buckland remarked, in his Evidence before the House of Commons, who have united the results obtained from their own observations with the conclusions of practical men, shews that we now know almost minutely the extent of all those districts in which coal can possibly exist in England.*

In those situations where the outcrop of the coal has been bared, either accidentally or by natural causes, or in the vicinity of well known coal fields, the chances of meeting with seams may, in most

* It does not appear that the virgula divinatorum, or divining rod, at one time in such estimation with our tin and lead miners, was ever in use among the colliers of this country, though to its use has been attributed the discovery of coal in France. "This kind of coally stone," says Schoock after Guicciardin," was discovered in the district of Liege, A.D. 1189, by a certain pilgrim, who, when he had pointed them out by a divining rod to a smith, suddenly disappeared; afterwards they began to be dug in great abundance." Morand tells us, in his Memoirs sur le Charbon de Terre, that the person who in the country of Liege first discovered them, is called "Prudhomme le Houilloux," or "le Veillard Charbonnier," "Hullasus Plenevallium"; that is, "the collier or blacksmith of Plenevaux," a village within two leagues and a half of Liege.

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cases, be easily calculated. In the districts on the Tyne and Wear, not only are sections of coal-basins exposed in the sides of vallies, but the basset-edges of the measures used formerly to be broken up in considerable quantities by the wheels of carts passing over them. In the Yorkshire coal-field, the outburst of the coal may frequently be noticed; and there may at this time be seen in the western suburb of the town of Sheffield, so large a surface of coal uncovered during the making of one or two new streets, that not only were the bricks of which many of the houses have been built, made of clay got out of the cellars, and burnt with the coal dug on the same spot, but the latter, although of a tender and indifferent quality, continues to be sold and carted away in considerable quantity. To persons remote from the colliery districts-and, indeed, to many others, the appearance of an acre or two of coal lying exposed in situ on a level with the street, must be a novel sight.

It is only, however, in some situations, and under particular circumstances, that denuded strata present themselves; hence, one chief difficulty which arises in exploring a country in search of coals, or even where coal fields are known to exist, arises from the great thickness of alluvial cover, which completely hides the crop or outburst of the strata, termed genenerally by miners the rock-head, from our view, and also completely conceals the fissures, dykes, and dislocations of the strata, which produce such material alterations in the coal fields, and are frequently the occasion of great loss to the mining adventurer. The alluvial cover has been compared, in reference to the strata which exist underneath, to the flesh upon the