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24 payment of fixed rent, in order to enable them to make a search for other minerals besides those to which they were entitled by the terms of the lease, with a view to working them, if discovered, on other terms. Time wore on; and in 1852, two years from the date of the lease, circumstances came to the knowledge of the proprietor, from which he gathered that the lessees were turning out a valuable substance, not comprehended by the terms of the lease, neither coal nor any of the other minerals therein specified; and after satisfying himself upon the point, the owner of the property intimated to the tenants that the working of this substance must cease, while the tenants, taking a different view, maintained that they were working a gas-coal, to which they were entitled by the terms of the agreement.

Thus a controversy arose, and in order to aim at a decision of the question, an action was brought by the proprietor of the lands at Tarbanehill against the tenants, who were said to have infringed the terms of the lease by carrying away a substance that was not coal, but some other valuable mineral.

With a view to obtaining a conclusion which should be based on scientific data, Europe was searched for men of mark in the scientific world. Men who had arrived at the highest eminence in natural philosophy—men who had devoted themselves to the study of physical science—men who had made geology their leading study—men whose attention to microscopic botany peculiarly fitted them for forming an opinion—men who arrived at their conclusions by means of the study of mineralogy and chemistry—and, lastly, men who had passed their whole time in mines or mining pursuits were summoned to declare their views upon this vexed question.

Yet was it in no degree set at rest. After six days of debate, the philosophers, the geologists, the microscopists, the histologists, the mineralogists, the chemists, the miners, and the managers have, on the one side, such strong testimony that the substance was not coal, that the matter would have seemed clouded by no doubt, had not a similar array of evidence on the other side unhesitatingly brought arguments to show that it was coal, thus rendering arbitration on the subject more difficult and more remote than ever.

In order to understand how such contradictory arguments could be adduced on this celebrated trial, we must endeavour to have a general conception of what is intended by the term coal.

Looking back to that remote and indefined period “dateless as eternity,” and described by Coleridge as a state rather than a time, we recede into those extinct creations of a strange order, which constitute the penetralia of the carboniferous forest, and enter the period of the gigantic and magnificent flora of the coal measures. There, in that ancient scenery, with its amazing development of vegetation, unique in the history of creation, forms arose amid the steaming vapours of the time in rich and luxuriant grandeur. Amongst forests of arboraceous ferns, tall as trees, sprung up huge club masses, thicker than the body of a man; and thickets of Equisetaceæ or horse-tail, of prodigious growth, covered the marshes. There flourished the Vlodendron with its strips of cones adorning in vertical rows its carved trunks, its stems covered with leaf-like carvings, passing in elegance the minutest tracery of which we have any conception. There grew the Sigillaria, remarkable for their beautifully sculptured and tattooed stems, varying in pattern according to their species, and longitudinally lined with rows of leaves bristling from the stems and larger boughs, while their roots or stigmaria were fretted over and ornamented with eyelet holes curiously connected by delicately waved lines. There also gigantic Cacti, of intertropical growth, varied the landscape, and there too were Palms and Canes. Last and not least were the true forest trees of that era—the Pines and the noble Araucarians, the latter attaining a height of a hundred and fifty feet—three times that of our own forest trees. All these were loaded with cones; on all, cones were the only productions corresponding to fruit—fruit unfit and vegetation unadapted for food; and as in that age there were no herbivorous animals, there needed no provision in these primeval forests for such a race.

Yet the period of this flora was not less remarkable for its fauna; but it was an age of creeping things. There were reptiles and reptile fishes, which attained an enormous size, with defensive weapons of amazing strength, and some of them covered with enamelled scales of exquisite polish; there were sharks armed with razor-like teeth, with spines and with barbed stings; there were dragon-flies, snouted beetles and scorpions.

But—what is coal?

On the spot where the vast vegetation of the inconceivably remote carboniferous era flourished and decayed, we now find our beds of coal; to a depth of 10,000 feet, or nearly two miles, the coal beds or coal measures are in some places found to penetrate. Alternate seams of coal, of shale, of ironstone, of clay, and of rock, succeed each other through this great depth, in layers varying in thickness from a few inches to as many feet. For countless ages forests had their allotted growth, then a sudden submergence took place, and as the sea rushed in, a new feature in the landscape presented itself. On the then entombed vegetation, ridges of coral arose, forests of encrinites overlaid the forests of conifers, and produced in their turn beds of limestone, which again, deserted by the sea in its appointed time, afforded soil enough for trees whose rootlets required but little nourishment, and which flourished upon this new platform. These were again submerged when the sea rushed in, and corals and encrinites again set to work. How often these vast operations succeeded each other, and during what prolonged periods, there is no means of judging, except from the extended time which such growths must require. The world was old even then, and long anterior to these changes, unreckoned ages had gone by, producing formations of earlier date and longer process.

Thus we are brought to the close of the era denominated carboniferous—a period of gigantic vegetable growth, a period of ferns and conifers, a period of reptiles and fishes, a period having, like