34 BUILDING AND ROOF VENTILATORS OF METAL, WOOD AND COMBINATION METAL AND WOOD, OF THE STATIONARY AND ROTATING TYPES, METAL CONDUCTORS FOR CONDUCTING AIR TO OR FROM A VENTILATOR, METAL FRESH AIR INTAKES AND REGULATORS THEREFOR, STORM HEAD VENTILATORS COMPRISING ORDINARY STATIONARY, RAIN AND/OR SNOWPROOF VENTILATORS