Oh! The baby's little big toe! No, that is just a play to amuse the baby. This is a real pig. Then, it's "the squealy little fellow that pays the rent" of the Irish farmer. No, again. That pig is not sold until he is big and fat or he wouldn't bring much money. Another guess—pig iron.

Pig iron! Who ever heard of such a thing? Your papa has, for one. Ask him. Pig iron gets its name in the papers every day, just as wheat and cotton does. Turn any daily paper over to an inside page of fine print headed "The Markets." There you will find the prices of things people have to have, and that are bought and sold every day. Wheat and other grains and flour fill two columns; live stock or cattle, sheep and hogs one column; produce, such as butter and eggs, one column; cotton half a column; metals: ah, here it is—copper, tin, lead, iron. It says: " The Iron Age will say tomorrow : Pig iron is rising in price. The iron ore fleet of ships is all on the lakes. Rolling mills are working day and night shifts. Great activity in all lines of iron manufacturing."

What is pig iron? What does it look like? Where is it found? It isn't found. It is made of iron ore, as flour is made of wheat, although in quite a different way. And it looks something like a round, gray stick of stove wood. The story of iron—how it is mined and turned into a pig, how it goes to market and what happens to it afterwards, is long and thrilling.

There is iron in every country in the world. It is all through the earth, the soil, the water and the rocks, and in plants and animals. Some spring water tastes of iron, and is colored brown by it. When iron rusts it turns red. So soil that holds a good deal of iron dust is red, or red brown. Red tile and brick clays are. full of iron, and there is iron in your red blood. Doctors give you iron tonics when your blood is too pale. And they tell you to eat spinach and other very green vegetables, because they have iron in them.

Iron is never found in lumps so a blacksmith could dig a piece out of the ground and hammer it into a nail. But in the rock layers of many mountains there is so much iron that it pays to melt it out. Such rocks are called iron ores. Iron is so useful that men have been melting it out of the ores for thousands of years. It takes such a terribly hot fire to melt iron stone that every ancient people made a wonder story out of how it was first done. The Greeks, who thought different gods did all the hard and mysterious things, had a god of fire called Vulcan. He was supposed to live in a burning mountain where he melted the useful metals, and hammered them into shapes on his forge. That is why we call burning mountains volcanoes today.

If those old Greeks could see the blast furnaces, or volcano towers of fire, and the rolling mills and casting foundries of today, where thousands of tons of iron are melted, rolled, cast, drawn and hammered into shapes, they would open their eyes. The world has learned how to do everything in mining ores, carrying them, melting and working iron, so that iron is now one of the commonest things in use. There isn't any kind of work that men do, from hoeing a garden to pulling a train of cars in which iron is not used.