PIT-COAL, OR STONE-COAL. See COAL and LITHANTHRAX.
Mr Bertrand, in his Orythologie Dictionnaire, reduces all kinds of coals to six general classes, viz. 1. Lithanthrax lignosus; 2. Petrofus; 3. Terrestris; 4. Piecus; 5. Fissilis; 6. Mineralifus. He says, that the Scots coals are heavier, and burn not so well as those of Newcastle; that those of Liege burn quicker; and those from Brissac in Auvergne, and from La Fosse, burn with a more agreeable flame, &c. But Mr Morand, in his Nomenclature Raisonnée, distributes all sorts of pit-coals into four classes: In the first he places nine varieties, beginning with the gogat or succinum nigrum, to the variegated lithanthrax; in the second he reckons seven varieties, beginning with the lithanthrax elegantis stratus, to that facie granulata; and he forms the fourth class with the earthy and poorer kinds of fossil coals. He seems, however, to have been puzzled with the flaty coals, as he ranges them in a separate class, perhaps to shelter himself from the critical objections of those numerous superficial naturalists, who only look for the apparent configuration, without almost any regard to the component parts of fossils.
The coal-trade is of infinite importance to Great Britain, which never could have arrived at its present commercial eminence without it; and this eminence it will be impossible to retain if coal should ever become scarce. This we trust is not likely to be the case, though Mr Williams expresses great fears for it, and informs us that at Newcastle and in many parts of Scotland the mines near the sea are already wasted, the first consequence of which must be an enormous rise in the price. See his observations on this subject in his Natural History of the Mineral Kingdom, p. 156, &c. This author says, that coal was not discovered till between the middle of the 12th and beginning of the 13th centuries: it is therefore, according to him, 400 years since it was first
discovered in Britain, but they have not been in common use for more than 200 years. The same author gives us many pertinent observations on the appearances and indications of coal, instructions about searching for it, remarks on false and doubtful symptoms of coal; for all which, together with his observations on the different kinds of Scots coal, we shall refer our readers to the work itself; the first part of which, occupying the largest proportion of the first volume, is upon the strata of coal, and on the concomitant strata. See also our article COALERY.