The red-hot, liquid iron is run off from the bottom of the blast furnace, just as we might run off water, or any other liquid, from a tap. It flows into sand molds on the floor, and when it is cold it forms great blocks or pigs of cast-iron. The pigor cast-iron is again melted in great pots, in the puddling furnace, and left to cool, after which it is heated till it is red- hot and pliable, and in that state it is beaten for a long time with immense hammers, and cut up into bars while it is soft. It is then called wrought iron.
Lesson 24
The Cow
