Iron, in one or more of its several forms, has been used for about four thousand years, it was essential to the industrial revolution and it is still the principal metal of commerce. At first, and for centuries, ironmaking was a manual craft, the quantities were small and the metal was scarce. Then in the fifteenth century, means were devised for making iron on a larger scale and ironmaking began to develop into an industry. In the eighteenth and nineteenth centuries technology and the scale of production developed rapidly and new types of iron were introduced. One of these, steel,...