Page:A Treatise on Geology, volume 2.djvu/349

 CHAP. XI. greatest northern collieries would have been earlier by several years; let him be assured, that had practical application kept equal pace with geological theory, we should not have been startled, in 1851, by the discovery of immense bands of ironstone which were measured and described more than twenty years before; and let it be added, that because geology has of late years made itself heard, even from a distance, and because the principles of this science have been kept in view in the field, gold will in future be looked for in the places where it is likely to be found. A few words respecting the ironstone and the gold.

The lias shales of the Yorkshire coast are of a greater thickness, and contain a greater variety of valuable substances, than those of the south of England. Besides the jet, cement stone, and alum shale, there are bands of ironstone, sometimes amounting to sixteen feet in thickness, of quality equal to the average of the carbonates of a coal district. They lie toward the upper part of the lias deposits, above a certain series of sandy beds with peculiar and characteristic fossils, and below certain other beds extensively worked for alum. The stone can be obtained at so small a cost, that about 2s. 6d. a ton is a remunerating price to the adventurer. It is in such, immense quantity that an acre will yield from 20,000 to 50,000 tons, and it may be opened in a line of coast and a line of inland cliffs, at many points, and for very many miles of outcrop. Railways are now laid to it, furnaces are built near it, and hundreds of thousands of tons of it are set in motion annually from the hills of Cleveland. This great activity is of sudden growth, one of the wonders of 1851. It was said, what was geology doing, that this vast treasure of iron has been left for the practical man to discover? We reply, this ironstone was measured, its exact geological place marked, and its prominent localities designated, in printed type and coloured sections, more than twenty years previously!