The excellence of Sweden’s iron and steel has long been known the world over. Sweden produces approximately one per cent of the world’s total production of iron and steel, but her ore has been of such high grade that iron made from it has maintained its position as a standard for use in the manufacture of highest grade crucible steels. The very finest steels for cutlery and tools, and even the softer grades of steel of northwestern Europe, have been made from Swedish iron as a base. Iron ore, of course, is classified by geologists and chemists into varieties with such names as hematite, magnetite, siderite, etc., which here little concern us. To be worked at a profit, the iron content of the ore must be high with the smallest possible amounts of undesirable impurities, particularly phosphorus, sulphur, and silica. There are, however, certain impurities which are not undesirable, for instance, lime, which will act as a flux and neutralize the effect of some of the undesirable impurities. For these reasons the prices for iron ore are based on the iron content and modified by the relative amounts of undesirable and desirable impurities. Phosphorus is almost a domineering factor and at present approximately fifty cents a ton more is paid for Bessemer ore (that containing less than .050 per cent phosphorus) than for non-Bessemer ore. As might be expected the best ores have been the first used and the grade is constantly falling. Instead of the 66 per cent iron ores of some years ago those coming nowadays contain not much more than 59 per cent of iron and the Bessemer ores described above are getting scarcer, so that for some years practically all of the furnaces have been mixing with them as much higher phosphorus ore as could be used without pushing the phosphorus content of the mixture over the allowable limit. We often hear people surmising what is to become of us when all of the iron ore of this planet has been used. There is no harm in taking stock of resources and in this case it does us much good. It happens that each time the count is taken of iron ore available and that which under future and better methods of working can be utilized, we find ourselves immensely better off than the previous report had made out and we have less cause to worry about the future. The last inventory was taken by the extremely ambitious International Geological Congress held at Stockholm, Sweden, in 1910. It shows that the world yet has enough rich ore to make 10,192,000,000 tons of iron, and, a further supply of ore for 53,136,000,000 tons of iron, which could be used if necessary. So we will get along for a while yet. CHAPTER III THE OTHER RAW MATERIALS [Illustration: OLD CHARCOAL KILNS, NEAR NEGAUNEE, MICH. ]