“Just that,” replied Westinghouse.
Vanderbilt turned to his secretary: “Show this lunatic out and never let him trouble me again,” he said.
Kelly’s first attempt at purifying iron with oxygen was a failure. The blast was too strong and the iron, along with the impurities, was blown away in one gorgeous display of fireworks. But he was not to be discouraged, and after many experiments got the blast right, only to find that the metal which resulted was too soft, as the small percentage of carbon and other alloys needed to give the steel its hardness had been taken out.
To Robert F. Mushet, a Scotch ironmaker, belongs the credit for overcoming this difficulty. He came forward with a practical suggestion: “Burn out all your carbon and then put back what you need to make the metal hard.” Simple enough, but the others had not thought of it. And the thing was done.
The hissing, roaring volcano is easily handled by one man. As he watches the flame that pours from its mouth change from red to yellow and finally burn white, he touches a lever which turns the huge caldron on its axis, while workmen quickly shovel into it the required amount of carbon, silicon, etc. The converter is then further tilted and its contents emptied into a ladle which swings away with its load while the converter is charged afresh with iron.
Open-hearth steel, more popularly used nowadays than the Bessemer product, is made by a different process. As the name implies, the iron is changed into steel in large ovens, where it is mixed with the necessary alloys and purifying ingredients and a considerable amount of scrap. The proper melt being arrived at, the metal, now steel, is run off into ladles.
The open-hearth method has many obvious advantages. In the first place, it gives the steel a greater tensile strength. In the second, using as it does about 60 per cent. of iron and 40 per cent. of old metal, it is an important factor in conserving the natural ore resources of the country and of the world for future generations.
Times change and steel making with them. Open-hearth is fast supplanting Bessemer steel in all markets, and the day may not be far distant when Bessemer will be practically a thing of the past. But it must not be forgotten that the discovery of Kelly and Bessemer—to whose names should be linked that of Mushet—gave birth to the modern steel industry and made possible the age of steel. Open-hearth itself may one day yield to another process. In fact, a prominent steel manufacturer has suggested that electric steel will be the steel of the future.
All the newer steel plants are equipped with open-hearth furnaces. At Gary, Bessemer is not produced at all, and even the Carnegie Steel Co., which probably did more than any other concern to develop the Bessemer process, now has 133 open-hearth furnaces to 14 Bessemer converters. The Corporation altogether has 335 open-hearth furnaces and 38 converters.
The manner in which the newer process is displacing the older is best illustrated by some production comparisons. In 1901, the first year of the Corporation’s existence, the subsidiary companies produced 6,109,306 tons of Bessemer steel to 2,745,514 tons of open-hearth. It was not until 1909 that open-hearth production forged ahead, going to 7,508,889 tons against 5,846,300 tons of the other. But since that year its gain has been progressive and continuous. In 1919, open-hearth production was 12,412,131 tons compared with 4,788,242 tons of Bessemer.