 |
 |
The Hedworth Barium Co Ltd operated Cowgreen Mines, Langdon Beck, Nr Middleton-in-Teesdale from 1898 until they went into liquidation in 1922,mainly for barytes. They also had a works at Jarrow Slake during about the same period. See "Out of the Pennines" (Ed B. Chambers), 1997. The Simplex Copper Extraction Co Ltd was a quoted company, registered in 1903 and went intoliquidation in June 1907but I have no knowledge of its operations. Russell Wear