The Steel Business: A Ferocious Geyser
The squat, egg-shaped Bessemer converter seemed an unlikely candidate to lead a revolution in manufacturing. Yet when it roared to life in a geyser of flame, nothing could be more beautiful or more terrible.
The device transformed pig iron into steel, a process previously managed by highly skilled artisans working with small batches. With the Bessemer converter, relatively unskilled men could make vast quantities of steel cheaply. Carnegie invested heavily in the converters, installing them in his Edgar Thomson Steel Works at Braddock, PA.
In August 1875, the Bessemers at Edgar Thomson made their first blow. Cold air shot through the bottom of the vessels and through the molten iron. The heat increased tremendously, burning out impurities in the iron and forming steel. The process was simple, but the effect was extraordinary. In 1893 McClure's Magazine described the results:
Out of each pot roared alternately a ferocious geyser of saffron and sapphire flame, streaked with deeper yellow. From it a light streamed -- a light that flung violet shadows everywhere and made the gray outside rain a beautiful blue. A fountain of sparks arose, gorgeous as ten thousand rockets, and fell with a beautiful curve, like the petals of some enormous flower. Overhead the beams were glowing orange in a base of purple. The men were yellow where the light struck them, violet in shadow.... The pot began to burn with a whiter flame. Its fluttering, humming roar silenced all else.... A shout was heard, and a tall crane swung a gigantic ladle under the converting vessel, which then mysteriously up-ended, exploding like a cannon a prodigious discharge of star-like pieces of white-hot slag.... Down came the vessel, until out of it streamed the smooth flow of terribly beautiful molten metal. As it ran nearly empty and the ladle swung away, the dropping slag fell to the ground exploding, leaping viciously, and the scene became gorgeous beyond belief, with orange and red and green flame.
The Bessemer converter became obsolete by the 1930s, and the last Bessemer in North America went out of commission in the 1960s. The only remaining Bessemer shop on earth is operating in the Ural mountains of Russia.
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