January, 2004 -- Inventors are of two sorts. The first says: "Here is a principle. How can it be used?" The second says: "Here is a problem. How can it be solved?" Henry Bessemer, born on January 19, 1813, was an inventor of the second type. Wherever he looked, he saw problems, and often enough he saw solutions for them. With his restless, problem-solving mind, he was apparently the first person ever to earn his living as an inventor selling to the open market.
As he did so, however,
How the Problem Was Found
From the age of twenty to the age of forty,
Then, in 1853, the Crimean War turned
The problem lay in the chemistry of iron. Cast iron (iron with four percent carbon) was a relatively brittle metal but cheap because it came directly from the blast furnace. Wrought iron, from which all carbon had been laboriously removed in a batch-process, was tough but soft; unfortunately, it was expensive. Steel, which had about 1.5 percent carbon, was both hard and tough, but it had to be made from wrought iron by another batch-process, requiring still more labor. And if one wanted to cast steel, one also needed vast amounts of fuel to keep the metal liquid despite its high melting point. What
One day, while melting cast iron in a crucible, he noticed that some of the metal directly in front of the crucible's air jets had not melted, though that was the hottest part of the furnace. Evidently, the metal's melting point had been raised. But what had a higher melting point than cast iron? Pure iron. Apparently, the cast iron had been decarburized by the air jet alone.
Then, he had another idea. He knew that the combination of carbon with the oxygen in air gives off heat. Could the purifying reaction by itself produce enough heat to keep the resulting pure iron liquid? To find out, he decided to bubble air up through the cast iron. But the crux of the experiment was this: the crucible would not be surrounded by fuel.
It worked. The result was "a veritable volcano," and when it was over, a crucible full of pure, liquid iron remained. Evidently,
So, how have historians treated
This article was originally published in the January-February 2004 issue of Navigator magazine, The Atlas Society precursor to The New Individualist.