הביתהThe Victorian Atlasחינוךאוניברסיטת אטלס
לא נמצאו פריטים.
The Victorian Atlas

The Victorian Atlas

3 דקות
|
August 12, 2010

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, Bessemer was always looking for his big break, the invention that would make his fame and fortune. In 1853, he found it, and the result was the Steel Age.

HOW THE PROBLEM WAS FOUND

From the age of twenty to the age of forty, Bessemer lived the life of a journeyman inventor. He moved from embossed stamps, to recycled graphite, to mechanical typesetting, to gilt powder, to the ventilation of mines, to the compression of coal, to solar energy, to the manufacture of oil and varnishes, to the braking system of railway carriages, to the refining of sugarcane, to the manufacture of plate glass. "I was content," he wrote in his autobiography, "to hold on to everything that paid for time and capital employed in its production."

Then, in 1853, the Crimean War turned Bessemer's mind to armaments. He thought that the accuracy of cannons could be improved by firing a rocket-shaped projectile through a rifled interior. When the English army showed no interest, Bessemer took his project to France (Britain's ally) and there learned of a critical difficulty. An elongated shell had several times the weight of a spherical ball with the same diameter; the force needed to drive the heavier shell might well destroy a cast-iron gun.

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 Bessemer hoped to do was make cast iron somewhat tougher, by mixing it with expensive steel.

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. Bessemer set out to test his idea and found he was right.

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, Bessemer had struck on the biggest invention of his life. The conversion of cast iron to pure iron, without the tedious batch-process, was a tremendous advance. But Bessemer could also make cast steel, simply by stopping the decarburization process halfway. That was not simply a new process; it was a new age.

So, how have historians treated Bessemer and his achievement? I have written elsewhere about attempts to deny Bessemer credit for his invention, by saying it came from China, or it was stolen, or it was in the air ("The Steelmaster," The Objectivist Forum, July/August 1985). But to my mind, the true indictment of our culture presented by the case of Henry Bessemer is just this: In the 106 years since Bessemer died, no one has been sufficiently interested in his achievement to write a detailed, scholarly account of his life. Such is the esteem in which Atlases of production are held.

This article was originally published in the January-February 2004 issue of Navigator magazine, The Atlas Society precursor to The New Individualist.

About the author:
História
Perfis
Ciência e Tecnologia