00848nam0-22003011i-450-99000033948040332120001010000033948FED01000033948(Aleph)000033948FED0100003394820001010d--------km-y0itay50------baitay-------001yy<<A >>method of trapping the dust produced by pneumatic rock drillsBy P.S. Hay.LondonHis Majesty's Stationery Office192618 p., ill., tav., 24 cmIn testa al front.: Mines Department622Hay,Peter StewartMines DepartmentITUNINARICAUNIMARCBK99000033948040332104 191-32CI 0934DINCHDINCHUNINAING01