The town of Newcastle, in Northumberland, has been celebrated during several centuries for its very extensive trade in coal. It was first made a borough by William the Conqueror, and the earliest charter for digging coals, granted to the inhabitants, was in the reign of Henry III., in 1239; but in 1306, the use of coal for fuel was prohibited in London, by royal proclamation, chiefly because it injured the sale of wood, with which the environs of the capital were then overspread. This interdict did not, however, continue long in force; and coals may be considered as having been dug for exportation at Newcastle for more than four centuries. It has been estimated that there are twenty-four considerable collieries lying at different distances from the river, from five to eighteen miles; and that they produced, for an average of six years, up to the close of 1776, an annual consumption of three hundred and eighty thousand chaldrons, Newcastle measure, (equal to seven hundred and seventeen thousand, six hundred and fifteen chaldrons, London measure,) of which about thirty thousand chaldrons were exported to foreign parts. The boats employed in the colliery are called _keels_, and are described as strong, clumsy, and oval, each carrying about twenty tuns; and of these four hundred and fifty are kept constantly employed. In the year 1776 an estimate was made of the shipping employed in the Newcastle coal trade; and from this estimate it appears, that three thousand, five hundred and eighty-five ships, were during that year engaged in the coasting trade, and three hundred and sixty-three in the trade to foreign ports, their joint tunnage amounting to seven hundred and thirty-eight thousand, two hundred and fourteen tuns. As already said, it is a common opinion among geologists, that coal is of vegetable origin, and that it has been brought to its present state by the means of some chemical process, not at this time understood. This opinion is abundantly supported by the existence of vast depositions of matter, halfway, as it were, between perfect wood and perfect coal; which, while it obviously betrays its vegetable nature, has in several respects so near an approximation to coal, as to have been generally distinguished by the name of coal. One of the most remarkable of these depositions exists in Devonshire, about thirteen miles south-west of Exeter, and is well known under the name of Bovey coal. Its vegetable nature has been ascertained by Mr. Hatchet, in a set of experiments in which he found both extractive matter and resin, substances which belong to the vegetable kingdom.