Bessemer steel has been largely used for the manufacture of rails, rod, wire, pipe, merchant bar, etc., while open-hearth steel has gone into plate, boiler tubes, structural shapes, billets for axles, etc. Recently it is being used for rails and very many of the products which were formerly made from Bessemer steel. [Illustration: LOWER HALF OF A “BATTERY” OF MODERN GAS PRODUCERS ] It should not be inferred from this that Bessemer steel is no longer in demand or that it is not good steel. As you will notice from the table given in the last chapter, the production of Bessemer steel has not declined appreciably, if at all. The fact is that open-hearth steel production has been increasing at a great rate, while the production of Bessemer has remained stationary. With the growing scarcity of ores suitable for pig iron for Bessemerizing, the open-hearth process is becoming able to compete with the Bessemer process in the matter of cost. For some purposes the steel is considered to be a little more desirable, but, as is the case with many good things, the pendulum swings too far and there is no doubt that open-hearth steel is often demanded and used for purposes for which Bessemer steel would be just as good and perhaps better. For many years it has been said that the Bessemer process is “doomed.” This, of course, was because of the scarcity of low phosphorus ores. Just how “doomed” it is, it is perhaps impossible to say. Certainly it is still a very live process and the combining of processes, such as “duplexing,” will probably prolong its life. By the “duplex” process, molten blast furnace iron from the mixer is “desiliconized” in the Bessemer converter. Before too much of the carbon has been burned, the metal is transferred to a basic open-hearth furnace where the remainder of the carbon and most of the phosphorus is removed. By this method the advantages of the open-hearth and much of the speed of the Bessemer process are combined. The output of the open-hearth furnace is thus greatly increased. To-day all kinds of combinations of Bessemer, open-hearth, and electric furnace are being projected and it is difficult and likely impossible for any one to predict the future of any of the processes. Lest the metallurgical facts scattered through several chapters escape, let us summarize a little. Roughly speaking, the capabilities of and materials required for the processes are as follows—the chemical symbols for silicon, manganese, carbon, phosphorus, and sulphur being used for brevity: PROCESS REFINING CAPABILITY MATERIAL REQUIRED Crucible Process. Removes no metalloids, Very low Si. P. S. and but simply remelts. C. Acid Bessemer Process. Takes out Si. Mn. and Very low P. and S. C. (under 0.1%). Basic Bessemer Process. Takes out Si. Mn. C. P. Very high P. (2% and and some S. over).