Every boy knows that Edison has never followed the ideas of others in working out his inventions, and the poured house is no exception to his rule. It will be interesting to take a little look back over a part of Edison's life and see how he came to enter the cement-making business, and how, when he had his process down to a fine point, he said to himself, "It is cheap and easy to build a house or an office building of concrete in sections, why not build it all in one piece?" We shall see that no sooner had he asked himself this startling question than he began by making models, and satisfied himself that it was not only possible, but one of the cheapest and best methods of making small, simply arranged houses, such as could be bought or rented for a small sum. Although Edison has within the last few years brought his idea to a state where it can be put to practical use, he himself is not trying to push it commercially, as he has his other great inventions like the phonograph, storage battery, and the motion-picture machine. In fact, he is content to let it be worked out by others just so long as it fulfills his idea of giving to workingmen good houses at a low price. "Years ago, long before Edison had retired from active business affairs to give his whole attention to scientific research," said the scientist, as he and the boy walked about the laboratory, "he became interested in metallurgy, just as he was and always is interested in every other science where great difficulties must be overcome. In those days iron and steel were not used as extensively as they are now, but the scientists and leaders in the big industries saw that the day was coming when far, far greater quantities of iron ore would be needed to supply the great demand for steel to build skyscrapers, ships, machinery, and so on. Men were going farther and farther away in their search for iron ore, but Edison, with his never failing originality, said to himself that it was likely there was plenty of iron ore right around his laboratory in New Jersey if he only knew how to get at it. "For one thing," continued the boy's friend, "Edison had seen on the ocean beaches great stretches of white sand with millions and millions of little black particles sprinkled through them. He knew that the specks were pure iron ore. You can prove this to yourself by simply holding a good magnet close to a pile of such sand, and watching the iron particles collect."