On top of what you've said, Joseph Douglas and his father Henry Douglas (Henry James / Henry junior) must have had a routinely hazardous job, for there is also this account from Friday 21 August 1936 in the Derry Journal: A fall of rock at a quarry on the face of Keady mountain, near Limavady, on Wednesday, injured two men, Henry Douglas (60), of Terrydoo and his son, Joseph Douglas (28), who were engaged at quarrying operations. Without warning, a great mass of overhanging rock gave way and crashed down. Henry Douglas's injuries were slight, but his son was struck by a boulder and rendered unconscious. He was taken to the Roe Valley Hospital by ambulance suffering from concussion, and has not yet regained consciousness. Hopes are entertained for his recovery.