Henry Bessemer. A man who improved the quality of steel
Category: Famous peopleHenry Bessemer, who was born on January 19, 1813, inherited his love of inventing from his father. Old Bessemer had worked in Holland and helped to build the first steam-engine in that country. Later he designed a new kind of lathe and made some other inventions while he was in France before the French Revolution of 1848.
Henry was born in a small village near Hitchin, in Hertfordshire. He never cared much for toys or games or for playing with oilier children and loved to watch the old flour mill in operation down by the water.
At an early age Henry became interested in drawing. He spent hours in the fields where he sketched the farm animals or the leaves of trees. He soon became very good at modelling as well.
As he grew older, he longed to try his hand at making moulds of his models and then casting them in his father’s foundry. But his father did not allow him to enter the foundry alone. He allowed him to enter it only when he himself was there. This was because he did not want other people to know about the technicalities of his work. But Henry ignored this rule and every two months when the large melting furnace was xised found his way into the melting house. He was usually discovered, but he not only managed to do his casting but also discovered his father’s production secrets.
Old Bessemer soon understood that his little son was really very much interested in metals, and then he began to encourage him and to teach him.
Henry went to school. When he was fifteen he asked his father to let him leave school and work in his foundry: he wanted to learn more about metals. And his father agreed.
Henry loved his work. The experience also gave him a useful insight into technical draughtsmanship, an important branch of an inventor’s work, at which, with his natural gift for drawing, he soon excelled. After about a year Henry knew enough to begin to make articles of his own invention. One of these articles was a small machine for moulding tiny bricks out of white pipeclay. The bricks were quite useless, but young Bessemer was proud of his work.
First Inventions
Early in 1830, when Henry was seventeen, his father decided to leave Charlton where they then lived and to transfer his business to London. Henry was very glad when he was told of his father’s plan.
In London he decided to become an inventor. For a time he had many and varied ideas, but he met with no success in realising them. First he tried to cast metal ornaments in brass instead of in dull lead. He sold some of his new ornaments to gift shops, but he made only a small profit.
Bessemer then turned his attention to designing a new typesetting machine. At that time a printer had to pick out all his letters by hand. It was very tedious work.
Bessemer designed a machine with a key-board rather like that of a piano that sorted out the letters required in a fraction of the time simply by depressing the necessary keys. It was a clever invention, and it worked most efficiently. When it was tested it was found that an inexperienced printer could set 6,000 letters an hour whereas by the old hand method a skilled man could set only about 1,700 letters an hour.
In 1833, he started work at another idea. At that time all legal deeds and documents, to make them legal, were stamped with adhesive stamps. But these stamps were easy to forge, and also they could be removed from old and useless documents and used again. Bessemer discovered that the government were losing a lot of money each year by such frauds. So he began to work out a new system of stamping in which adhesive stamps were not used, and documents could be perforated with an impression of the stamp, which would be impossible either to forge or to remove.
His idea, however, was not adopted because a simpler process of only dating the stamps had become known by that time.
Bessemer soon met with a stroke of luck. He was asked by a London firm if he could work out some method of embossing velvet with figured designs. A number of firms had tried to impress designs on the velvet by means of heavy rollers, but their results were not good. The long pile rode up and the designs disappeared. No matter what they did, they could not keep the pile flat.
Bessemer, after a good deal of experimenting, decided that the only way to make a good impression on the velvet was to heat the material and to emboss it in that condition. There were many difficulties, Bessemer said later, but in the end he solved his problem. He designed a machine with a metal roller in which he arranged a number of burners. These burners kept the roller at a constant heat and the machine did the work perfectly.
Some time later his sister asked him to gild her volume of flower paintings. While he was doing this Bessemer hit upon a way of producing heap gold powder.
He built a large machine for grinding brass, and placed it in a room of his house. Then he started his own factory of gold powder.
More Useful Inventions
When his factory began doing so well, Bessemer again spent all his time working out inventions. During this period he designed a new press for extracting the juice from sugar-canes, a steam fan for ventilating mines and centrifugal pump for land draining, which could raise twenty tons of water an hour.
Bessemer also interested himself in railways. He invented a method of continuous braking for trains and introduced the use of luggage vans.
For the improvement of glass production he perfected the making of optical glass and invented a machine for making sheet glass.
His Greatest Discovery
Steel, a metal derived from iron but stronger and not brittle, was in itself no new thing: what was new was Bessemer’s process for manufacturing it. This process helped to produce steel cheaply and greatly changed engineering and industry throughout the world.
Before Bessemer’s discovery, steel was made out of brittle and very impure cast-iron by a long and laborious open hearth process. This steel was very costly. Also, it could be made only in small bars, and not in the large units in which it is now made. So steel could not be used for making heavy articles. Ships, railway lines, and, in fact, all heavy engineering works were made out of iron, which was much less strong. Steel was so costly that only about fifty thousand tons were produced in Britain each year.
Bessemer had built himself two new apparatuses for experiments. One was a special furnace and the other a melting bath. One day when he was blowing air over the top of the bath he saw that two little pigs of iron near the top did not melt. As they still did not melt even when there was more heat and the temperature in the furnace became maximum, Bessemer prodded them with a bar. Strangely enough, he found that they were no longer brittle like cast- iron. They had become plastic. This was because the oxygen in the air, which had come into close contact with these two pigs, had decarbonized them. This did not happen to the metal submerged in the bath because it was not in contact with the oxygen in the air. The two pigs had been decarbonized and had become malleable iron.
The discovery gave Bessemer a brilliant idea. He knew that to make steel he had to purify the iron. It could be done, he thought, not only by reducing the carbon content but also by removing the silicon and phosphorus in it. Then, when it had been purified, a very little carbon and some other chemicals were added to kill or calm the metal. It now occured to Bessemer that, by forcing a current of air through the molten iron in a closed bath or converter, the oxygen in the air might drive out the impurities in the iron. At the same time the impurities were carried away through the chimney. So he tried pouring some molten iron into a large cylindrical converter and blowing air into this.
The experiment was successful. Bessemer found that he had, in fact, purified his iron without any form of external heating. In doing so, he had also established a most important fact: that the process of oxidation (with the removal of the impurities) in itself automatically raises the temperature of the metal much higher than it is possible to attain by normal furnace heating, and that oxidation can be brought about just as easily by cold air as by hot air.
Bessemer’s next task was to design a better and less dangerous converter. After making several further experiments, he decided that oxygen would penetrate the molten metal more evenly, and the iron was purified more efficiently and quickly when the air was introduced through the bottom of the converter.
The Bessemer Process of Steel Production
So he built a new converter and it was most efficient. Bessemer could turn molten pig iron into high-grade steel in only about fifteen minutes.
Henry Bessemer patented his new process in 1856 without waiting to perfect his converter. But there were still many difficulties, and he had to overcome them before his system was adopted everywhere.
He was sure that his system was good and he decided to begin production himself. He built his own steel works in Sheffield and was soon producing very cheap steel. He could produce it in large sheets and not only in small bars.
It was possible to use his steel in the construction of ships, bridges, railway lines, and in other large engineering and industrial works.
When Bessemer first suggested the use of steel for railway lines which was a great novelty at the time to the chief engineer of the London and North Western Railway, the latter was quite angry. “Mr. Bessemer, do you wish to see me tried for manslaughter?” he said.
But experience showed that Bessemer’s steel was of such high quality and so efficient in every way that the demand for it grew quickly. By 1880 Bessemer’s factory was producing 830,000 tons of steel a year—nearly seventeen times more than the whole country had produced by the puddling process.
As the Bessemer process of steel production became accepted everywhere, Bessemer himself came to be regarded as one of the great inventors of the 19th century; and lie received many awards and honours. In 1871 he was elected President of the Iron and Steel Institute, and eight years later he was also elected a Fellow of the Royal Society.
The United States of America, who had founded her own steel industry on the Bessemer process, named two towns after him.
Henry Bessemer retired in 1879, but even after his retirement, he still led a very busy life and continued to do so until only a year or two before his death at eighty- five.
Besides the new process of steel production, he made some inventions: machines for polishing diamonds and grinding mirror glass; a method of asphalt paving; and a ship with a special kind of rotating saloon that always remained in an upright position, no matter how much the ship itself rolled. This ship was built to save passengers from seasickness. Bessemer also carried out experiments with a new telescope and with a solar furnace. He was always trying some new idea.
Henry Bessemer was one of the most successful inventors of his day. He received more than one hundred and fifty patents. His achievements were remarkable because the only practical experience that he had ever received in either metallurgy or engineering before he began his work was the few years that he had spent in his father’s foundry. He had received no proper training, but had acquired nearly all his technical knowledge in the course of his own researches. His success was due to his personal characteristics—to his inventive mind, his energy, as well as to his superb skill as a draughtsman. Perhaps most important of all was his confidence of success.