When an open-hearth furnace is tapped a big ladle is brought into position, a workman runs a crowbar through the clay stopper holding back the molten metal, and it runs out like buttermilk from a churn. What slag accompanies it rises to the top as oil on water and overflows the sides when the ladle becomes full of the melted steel. Once filled, the ladle is picked up by a crane and its contents dumped into molds to harden into ingots. This is the first process in making the major portion of the country's steel and is now almost exclusively used in making steel rails.