Surely there is not in the world an industry which, for sheer pictorial magnificence, rivals the modern manufacturing of steel. In the first place, the scale of everything is inexpressibly stupendous. To speak of a row of six blast furnaces, with mouths a hundred feet above the ground, and chimneys rising perhaps another hundred feet above these mouths, is not, perhaps, impressive, but to look at such a row of furnaces, to see their fodder of ore, dolomite, and coke brought in by train loads; to see it fed to them by the "skip"; to hear them roar continually for more; to feel the savage heat generated within their bodies; to be told in shouts, above the din, something of what is going on inside these vast, voracious, savage monsters, and to see them dripping their white-hot blood when they are picked by a long steel bar in the hands of an atom of a man—this is to witness an almost terrifying allegory of mankind's achievement.
The gas generated by blast furnaces is used in part in the hot-blast stoves—gigantic tanks from which hot air, at very high pressure, is admitted to the furnaces themselves, and is also used to develop steam for the blowing engines and other auxiliaries. In the furnaces the molten iron, because of its greater specific gravity, settles to the bottom, while the slag floats to the top. The slag, by the way, is not, as I had supposed, altogether worthless, but is used for railroad ballast and in the manufacture of cement.
The molten iron drawn from the blast furnaces runs in glittering rivulets (which, at a distance of twenty or thirty feet, burn the face and the eyes), into ladle cars which are like a string of devils' soup bowls, mounted on railroad trucks ready to be hauled away by a locomotive and served at a banquet in hell.
That is not what happens to them, however. The locomotive takes them to another part of the plant, and their contents, still molten, is poured into the mixers. These are gigantic caldrons as high as houses, which stand in rows in an open-sided steel shed, and the chief purpose of them is to keep the "soup" hot until it is required for the converters—when it is again poured off into ladle cars and drawn away.
The converters are in still another part of the grounds. They are huge, pear-shaped retorts, resembling in their action those teakettles which hang on stands and are poured by being tilted. But a million teakettles could be lost in one converter, and the boiling water from a million teakettles, poured into a converter, would be as one single drop of ice water let fall into a red-hot stove.
In the converters the metalloids—silicon, manganese, and carbon—are burned out of the iron under a flaming heat which, by means of high air pressure, is brought to a temperature of about 3400 degrees. It is the blowing of these converters, and the occasional pouring of them, which throws the Vesuvian glow upon the skies of Birmingham at night. The heat they give off is beyond description. Several hundred feet away you feel it smiting viciously upon your face, and the concrete flooring of the huge shed in which they stand is so hot as to burn your feet through the soles of your shoes.
The most elaborate display of fireworks ever devised by Mr. Pain would be but a poor thing compared with the spectacle presented when a converter is poured. The whole world glows with golden heat, and is filled with an explosion of brilliant sparks, and as the molten metal passes out into the sunlight that light is by contrast so feeble that it seems almost to cast a shadow over the white-hot vats of iron.
Next come the tilting open-hearth furnaces, where the iron is subjected to the action of lime at a very high temperature. This removes the phosphorus and leaves a bath of commercially pure iron which is then "teemed" into a hundred-ton ladle, wherein it is treated in such a way as to give it the properties required in the finished steel. What these properties may be, depends, of course, upon the purpose to which the steel is to be put. Rails, for example, must, above all, resist abrasion, and consequently have a higher carbon content than, say, reinforcing bars for concrete work. To obtain various qualities in steel are added carbon, ferro-manganese, or ferro-silicon in proportions differing according to requirements.
In the next process steel ingots are made. I lost track of the exact detail of this, but I remember seeing the ingots riding about in their own steel cars, turning to an orange color as they cooled, and I remember seeing them pounded by a hammer that stood up in the air like an elevated railroad station, and I know that pretty soon they got into the blooming mill and were rolled out into "blooms," after which they were handled by a huge contrivance like a thumb and forefinger of steel which—though the blooms weigh five tons apiece—picked them up much as you might pick up a stick of red candy.