The forerunner of the modern steels was crucible steel, first made by Huntsman about the middle of the eighteenth century. Previous to his time steel had been made by the “cementation” process by which method hammered-out bars of wrought iron were given a hard steel crust by heating to a red heat in charcoal or bone dust. Huntsman’s product began to come so uniform and of such quality that his competitors were quite outdistanced. It is related that one of them took advantage of a very severe storm to gain admittance to the forest forge of Huntsman, who, he knew, could not refuse shelter at such a time. What he beheld was a very simple thing—the melting in a clay pot of pieces of cementation steel. Even to-day the crucible process is holding its own where quality is the main consideration. It is the method by which practically all of the tool, automobile, and other special steels of to-day are manufactured and can hardly be given too high a rating. The newly devised electric furnace process is the only possible competitor in sight. Of course for quantity and for lower cost the Bessemer and the open-hearth processes are the only available ones, but crucible steel has been the mighty factor in the commercial development of the world—at least until the latter half of the last century when the two other processes last mentioned began to acquire honor of their own without, however, detracting much from the importance of crucible steel as the steel of “quality.” [Illustration: THE FIRST IRON CASTING MADE IN AMERICA ] Though more interesting than any of the “six best sellers” much of the subsequent history of iron will have to be passed over at this time. We can now only mention those very great and revolutionary discoveries and inventions which led to and absolutely are the basis of the quantity and excellence of modern irons and steels; namely, the trial for a time of coke made from pit coal by Dud Dudley of England and its failure which was turned into a great success a century later (about 1713) by Abraham Darby; Watt’s invention of the steam engine in 1770 which made possible application of a strong continuous blast; invention of the process of “puddling” of iron and of the rolling mill by Cort about 1784; the introduction by Neilson about 1830 of the hot instead of the cold blast which increased blast furnace production fourfold; the regenerative system of furnace heating invented by Frederick and William Siemens; and the invention of the Bessemer and Siemens-Martin or open-hearth processes which provided methods for steel making on such an immense scale that this invaluable material was made available for general purposes.