National Geographic : 1947 Apr
Man's Mightiest Ally ) atlonal ieograpnic society Kodachroioc by \Willard It. Culvcr Dynamite Tears Iron Ore, Mother of Steel, from the Mesabi Range's Embrace Deep in a Minnesota mine, these men insert explosive charges in the rock wall. Wires connect the fuses to a battery-box detonator placed at a safe distance. Automatic conveyors will'load ore into rail cars for the trip to the shaft's mouth. Mesabi ore is mined both underground and on the surface (Plate X).