Nine people in ten, I suppose, do not know the chemical difference between iron and steel. Iron is iron; but steel is iron mixed with carbon. But, then, what is carbon? There is no substance in nature of which you can pick up a piece and say, This is carbon. And hence it is difficult to explain its nature and properties. Carbon is the principal ingredient in coal, charcoal, and diamond. Carbon is not diamond, but a diamond is carbon crystallized. Carbon is not charcoal, but in some kinds of charcoal it is almost the whole mass. As crystallized carbon or diamond is the hardest of all known substances, so also the blending of carbon with iron hardens it into steel. The old way of converting iron into steel was slow, laborious, and expensive. In India for ages the process has been as follows: pieces of forged iron are put into a crucible along with a certain quantity of wood. A fire being lighted underneath, three or four men are incessantly employed in blowing it with bellows. Through the action of the heat the wood becomes charcoal, the iron is melted and absorbs carbon from the charcoal. In this way small pieces of steel were made, but made at a cost which confined the use of the article to small objects, such as watch-springs and cutlery. The plan pursued in Europe and America, until about twenty-five years ago, was similar to this in principle. Our machinery was better, and pure charcoal was placed in the crucible instead of wood; but the process was long and costly, and only small pieces of steel were produced at a time. Henry Bessemer enters upon the scene. In 1831, being then eighteen years of age, he came up to London from a country village in Hertfordshire to seek his fortune, not knowing one person in the metropolis. He was, as he has since said, "a mere cipher in that vast sea of human enterprise." He was a natural inventor, of studious and observant habits. As soon as he had obtained a footing in London he began to invent. He first devised a process for copying bas-reliefs on cardboard, by which he could produce embossed copies of such works in thousands at a small expense. The process was so simple that in ten minutes a person without skill could produce a die from an embossed stamp at a cost of one penny.