"Coal is very extensively worked in this township [Crook and Billy Row], principally by Messrs. Pease & Partners, who have in addition to five pits a large number of coke ovens and a large fire brick works situated at Bank Foot. Here is produced the well known "Pease's West" coke. Amongst the ovens are a number of the Simon Carves type, the gases from which produce large quantities of sulphate of ammonia, benzol oil, and coal tar, as bye products. The collieries at present worked by this firm in this parish [Crook] are Roddymoor, sunk in 1844, where five seams are met, the "Main Coal" seam being 3 feet 9 inches thick, and 34 fathoms deep ; the "B" Seam, 2 feet 4 inches, 25 fathoms deep ; "Five Quarter," 3 feet 6 inches, 16½ fathoms ; "Ballarat," 1 foot 10 inches, 12½ fathoms ; and the "Yard," 3 feet, at a depth of 11 fathoms."

Whellan's 1894 Directory of County Durham (via Durham Mining Museum)