INDUSTRY'S GREATEST ASSET— STEEL 



151 



ment. He finally succeeded in getting the 

 amount of air regulated, and poured out 

 of his converter the first Bessemer steel. 

 People said Kelly would soon be burning 

 ice. Since his old converter was first 

 used, billions of dollars' worth of steel 

 has flowed out of the world's converters. 



DANTE'S DREAMS OUTDONE 



Both Kelly and Bessemer were baffled 

 by the problem of regulating the supply 

 of air so that it would not burn out all 

 the carbon, a little of which is essential 

 to steel. Furthermore, their products 

 frequently proved to be brittle, owing to 

 the fact that the molten metal absorbed 

 oxygen from the air blast. The first 

 difficulty was solved eventually by the 

 expedient of burning out practically all 

 the carbon, then adding exactly the 

 amount required for the specific quality 

 of steel desired. The second difficulty 

 was overcome through the addition of 

 manganese to take care of the hurtful 

 oxygen. The latter suggestion was the 

 contribution of Robert F, Mushet, a 

 Scotch steel maker. Goransson, a Swed- 

 ish ironmaster, had previously achieved 

 the same results by using a pig iron 

 initially rich in manganese. Thereafter 

 underdone and overdone steel disap- 

 peared. 



To go into a great building where there 

 is a battery of Bessemer converters is to 

 see more heat than Dante ever pictured. 

 A converter is a huge egg swung "amid- 

 ships" on trunnions. The great egg of 

 steel lined with fire-brick has the top off. 

 Some twenty tons of molten pig are 

 poured into it, and then through some 

 two hundred little holes in the bottom 

 powerful engines pump in a stream of 

 cold air. As the oxygen-laden air sweeps 

 up through the molten iron, it touches 

 the molten carbon and silicon, which con- 

 stitute the impurities, and carries them 

 away. Millions of red and white sparks 

 fill the air, as if some demon within the 

 fiery fluid were giving a pyrotechnic per- 

 formance. A thousand engines, with 

 safety-valves hissing under tremendous 

 pressure, have the voice of a zephyr in 

 comparison. First the flame that pours 

 forth is violet, then shades into orange, 

 becomes a dazzling white, burning finally 



to a faint blue, which is a sign that all 

 the impurities are gone. 



Then the blast ceases, the carbon that 

 is necessary to replace the needed por- 

 tions burnt out is added, the great brick 

 and steel egg swings back to position, the 

 carbon is mixed with the fervent fluid, 

 and then the egg tips over on its side, and 

 out of the top flows the liquid steel into 

 a great ladle. When it is swung back 

 into position, a man with colored glasses 

 walks out over the converter and peers 

 down into its white-hot depths to see if 

 the heat from the last charge has melted 

 away any of the fire-brick lining. If it 

 has, he hurls balls of putty-like clay down 

 into the holes to stop them up, or sets a 

 crew of workmen to patching the dam- 

 aged shell. This done, the big egg swings 

 back again, gets another charge of mol- 

 ten iron, and begins the process over 

 again. The whole operation takes about 

 20 minutes — a ton of steel a minute. 

 Bessemer steel is used for structural ma- 

 terial, railroad rails, wire, and pipe. 



In 1900 there was twice as much steel 

 produced in the United States by the 

 Bessemer as by the open-hearth process. 

 But with the rapid exhaustion of ores 

 having the proper amounts of phos- 

 phorus for converter practice, the open- 

 hearth furnace, which can use with equal 

 success ores which contain either a large 

 or a small amount of phosphorus, largely 

 replaced the Bessemer converter. 



A TINTED POOL 0E LIGHT 



An open-hearth furnace looks a good 

 deal like an ordinary bake-oven ; but 

 when one looks in through the water- 

 cooled door, a vast difference appears. 

 Instead of pans of fragrant, fat loaves 

 of baking bread, there is an imposing 

 pool of fiery liquid as bright as the fila- 

 ment of a high-power tungsten lamp, so 

 dazzling that it can be examined with 

 safety to the eyes only by those using 

 colored glasses. Tinted here and there 

 with streaks of soft blue and dainty pink, 

 it looks like melted stick candy. 



In preparing a battery of open-hearth 

 furnaces for a charge, finely ground 

 dolomite is shoveled in first. This melts 

 like glass and fills up all cracks and cran- 

 nies caused by the powerful heat of the 



