Susan Collins, Age 10, Of Charleston, Gt. Va., for her question:

What is pig iron?

Our cavemen ancestors lived in the stone age, for most of their tools and weapons were made from stone. We live in the iron age, for most of our machines and weapons are made from iron and steel. All the varieties of iron and steel are made from pig iron. But even if you watch this work done, you would never guess why pig iron is called pig axon.

Pig iron is used to make cast iron for pipes and heavy engine blocks. Pig iron Is used to make wrought iron for fancy garden furniture. Pig iron is used to make all The different kinds of shirty steel. For making steel, molten pig iron is run from a Searing blast furnace t0 a searing mixer where it will be heated and purified and Mixed with other materials. All the pig iron used in the recipes for making irons and steels comes from a Blast furnace. Here the pig iron is extracted from ores, the rocky minerals in which Iron is mixed with other substances. The blast furnace is a whopping cylinder, perhaps 30 feet wide and taller than 20 men. It is made of sturdy steel and lined with clay Bricks to prevent the steel walls from melting in the terrific heat. The cylinder is loaded with lumps of iron ore, limestone and coke. This coke is A cindery substance made from coal that has been heated to drive off some of its gases. In a blast furnace., coke is better than ordinary coal. A blast of seething hot air is Sent into the furnace, and the solid lumpy mixture melts to a runny molten mixture. The heat causes the chemicals in the brew to separate, and the heavy iron sinks To the bottom. The iron from this process is called pig iron. Same of it is taken to A casting machine, poured into brick molds and allowed to cool. The solid bars of metal have been cal1ed pigs since before the blast furnace was invented. In the past, a stream of molten iron ran from the furnace into a row of molds. This operation reminded iron workers of a mother pig feeding her piglets. The main trough of molten iron was called the sour, and the molds waiting to be filled were called Pigs. When the metal cooled in the molds it was called pig iron, and it is called pig iron to this day.

Pig iron is a brittle and rather soft metal, for it contains perhaps 5% carbon and other impurities. It must be remelted to become durable cast iron. To make workable wrought axon, the pig iron is remelted, pressed and squeezed. Steel is an alloy in which remelted pig iron is highly purified and mixed with other metals and minerals.