BIRTLEY, a township, in the parish and union of Chester-le-Street, Middle division of Chester ward, N. division of the county of Durham, 3 miles (N.) from Chester-le-Street; containing 1759 inhabitants. In Bishop Hatfield's time this place belonged to a family of its own name, and subsequently formed part of the forfeitures of the Earl of Westmorland, on the attainder of that nobleman. The township comprises 1344 acres, of which two-thirds are arable land; the surface is undulated, the soil chiefly clay, and the views, which are very extensive, embrace Lumley and Lambton Castles, and Ravensworth vale. Coal is abundant throughout the township; and freestone is quarried for building purposes, and for grindstones. Salt-works were in operation here at a very early period: Sir William Lambton, in his petition to parliament, particularly enumerates, among other losses inflicted by the Scottish army, the total destruction of his "salt-works" at Birtley. In the latter part of the last century a strong brine-spring was discovered, which now produces about 1200 tons of salt per annum: the brine is conveyed from the spot whence it issues, to the bottom of a coal-pit, from which it is raised in pumps by the colliery steam-engine. Large iron-works were established in 1829, in which pig and bar iron, castings and engines are made, employing nearly 200 hands. There are several railways for conveying the coal; at Ouston colliery is a railway passing to the Tyne, distant six miles: the road from Durham to Newcastle, also, intersects the township. A full church service is performed in a licensed chapel every alternate Sunday. There is a place of worship for Wesleyans; also a Roman Catholic chapel.