"Coal mining operations have been extensively carried on in Byers Green township for many years, the royalties being now worked by Messrs. Bolckow, Vaughan, & Co., at their pit, which was sunk in 1877. Here are two seams, the "Busty," 48 fathoms deep, having a section of 4 ft. with a band varying from inches to feet. The "Brockwell" seam is met at a depth of 76 fathoms, and is 3 ft. 10 in. thick. The two seams yield an average output, when in full operation, of 640 tons per day, and give employment to 600 men and boys. The coal is chiefly converted into coke, for which purpose there are 353 ovens. The "Beaumont" and "Harvey" seams are also met here."

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