(c)examine into, and make inquiry respecting, the state and condition of any mine or any part thereof, the ventilation of the mine, the sufficiency of the bye-laws for the time being in force relating to the mine, and all matters and things connected with or relating to the health, safety and welfare of the persons employed in the mine, and take whether on the precincts of the mine or elsewhere, statements of any person which he may consider necessary for carrying out the purposes of this Act;