In various parts of the world copper always has occurred “native”; i.e., in the metallic form and not in combination with other elements as an earth or ore. As the centuries rolled on, man eventually learned that this soft red metal could be pounded into thin-edged implements and that it made more useful tools than those of stone, which his ancestors had taught him to form. Some of these metal implements were hard and had fairly good cutting edges, made so by accidental or intentional presence of tin, and little did he dream that the twentieth century upon finding his buried bronze implements would think his crude alloy so wonderful and talk reverently of a “lost art of tempering copper.” [Illustration: IMPLEMENTS OF THE STONE AGE ] Gold, too, became known to him because it also occurs “native.” Its melting point was low enough that he could fashion it into ornaments, idols, and other articles for religious purposes. But during the hundreds of centuries of the “Stone Age” and during much of this—the “Bronze Age”—copper, bronze, and gold were the only metals used. Though the smiths became very dextrous in casting and modeling these metals, they yet knew not iron or steel. [Illustration: IMPLEMENTS OF THE BRONZE AGE ] Round about them during these many centuries, as multi-colored earths or rocks, were the ores of various metals. They little dreamed that when rightly treated certain of the heavy red, yellow, or black earths which lay right at their doors could give up that most useful metal, iron. No one even had knowledge of such a substance, for, unlike copper and gold, iron never occurs “free,” having too great a tendency to chemically combine with other elements, for example, oxygen of the air, with which, in moist climates, it so readily forms “iron rust.” Besides, its melting point is high and so much heat and carbon are needed for its “reduction” from the ore that, during the thousands of years that had gone before, it had never been produced. [Illustration: PRIMITIVE FURNACE FOR SMELTING IRON ] But one day by accident and under fortunate coincidence of rich ore, high heat, and plenty of carbon in the form of charcoal from the wood, a lump of metallic iron was formed underneath a pile of logs which had got afire and burned fiercely because of a high wind. When pounded between two stones this new heavy metal, too, was malleable and could be formed into a spearhead superior to anything yet known. Every one was interested and an observant one soon “doped out” that certain earths could be made to yield this new metal, iron. The art of extracting it spread slowly, each artisan learning from his neighbor, and, as rich ores were plentiful in many districts, iron became more and more generally produced. Not only in one country was this so but evidence shows that in many others—in Egypt, Chaldea, Borneo, India, China, etc.,—roughly similar processes and crude furnaces came to be used.