ironstone is found in the shale, forming either thin subordinate strata, or nodules; at Aldstone and in Teesdale it occurs forming septaria with internal divisions, such as are represented in St. Fond's travels; and at the latter place it forms the œtite or eaglestone of the old mineralogists. It is more abundant in the shales of this formation than in those of the Coalfield, but the only iron work now existing within the limits of my map is that of the Tyne company at Lemmington 3 miles west of Newcastle. The Carton company formerly collected on Holy Island a part of the ore smelted at their furnaces, but they have long since relinquished this undertaking.
About the beginning of the last century, according to Wallis, an iron manufactory was established at Lee Hall, in the vale of North Tyne near to Bellingham. The director of it was a Mr. Wood, son of the Irish projector of that name. The ore was plentiful in the strata of a romantic precipice on the east side of the river, and a good deal of bar iron was made from it; but it seems that charcoal becoming scarce the work was relinquished. Large quantities of slag are still found scattered over the surface, or forming considerable mounds, wherever the Romans carried their roads or fixed their stations.
The variety of carbonate of lime called satin spar, forms a thin stratum in a bed of black slate-clay, which crops out at Aldstone close to the brewery. The specimens are generally intersected by veins of iron pyrites and slate-clay. Some buildings stand upon the bank out of which this mineral was quarried, and the proprietor to save them from being undermined has built a wall close to the face of the rock; so that satin-spar is no longer to be procured, and is become a scarce mineral.
There are few parts of the Lead-mine district in which coal is
