sold the quarry to Cadwalader Owen Roberts of Betws-y-Coed for a nominal sum.

The quarry continued operating under the name the New Welsh Slate Quarry. Cadwalader Pierce took over as manager in 1911 repairing some of the damage from the rock fall. The quarry continued producing until 1912 but after that only already worked slate was dispatched and the quarry closed again in April 1914. Roberts reopened Cwt y Bugail in 1919 after the end of the First World War and