When I became my father's helper he began teaching me to handle the machinery of the trade. The puddling furnace has a working door on a level with a man's stomach. Working door is a trade name. Out in the world all doors are working; if they don't work they aren't doors (except cellar doors, which are nailed down under the Volstead Act). But the working door of a puddling furnace is the door through which the puddler does his work. It is a porthole opening upon a sea of flame. The heat of these flames would wither a man's body, and so they are enclosed in a shell of steel. Through this working door I put in the charge of “pigs” that were to be boiled. These short pieces of “mill iron” had been smelted from iron ore; they had taken the first step on their journey from wild iron to civilized iron. There isn't much use for pig-iron in this world. You've got to be better iron than that. Pig-iron has no fiber; it breaks instead of bending. Build a bridge of it and a gale will break it and it will fall into the river. Some races are pig-iron; Hottentots and Bushmen are pig-iron. They break at a blow. They have been smelted out of wild animalism, but they went no further; they are of no use in this modern world because they are brittle. Only the wrought-iron races can do the work. All this I felt but could not say in the days when I piled the pig-iron in the puddling furnace and turned with boyish eagerness to have my father show me how. Six hundred pounds was the weight of pig-iron we used to put into a single hearth. Much wider than the hearth was the fire grate, for we needed a heat that was intense. The flame was made by burning bituminous coal. Vigorously I stoked that fire for thirty minutes with dampers open and the draft roaring while that pig-iron melted down like ice-cream under an electric fan. You have seen a housewife sweating over her oven to get it hot enough to bake a batch of biscuits. Her face gets pink and a drop of sweat dampens her curls. Quite a horrid job she finds it. But I had iron biscuits to bake; my forge fire must be hot as a volcano. There were five bakings every day and this meant the shoveling in of nearly two tons of coal. In summer I was stripped to the waist and panting while the sweat poured down across my heaving muscles. My palms and fingers, scorched by the heat, became hardened like goat hoofs, while my skin took on a coat of tan that it will wear forever.