Raw Steel Bars
            In the beginning of the 19th century most metal objects were made of wrought iron, because steel was expensive.  Engineers preferred wrought iron since it was easy to make and very inexpensive. A metal that could withstand severe heat and was able to bear extreme weight had been needed for over a century.  The idea came to Bessemer after he had developed a new type of cannon shell. This shell had a lasting effect on the cannon, causing them to become nonfunctional.     

            He started off experimentation with his brother in-law Baxter House, who assisted him in St. Pancras. As a basis Bessemer used his knowledge of cast steel to choose his materials.  With the weight of many intuitions and industries a failure would be catastrophic. Using a small furnace he chose pig iron; a product of smelting ore and blister steel to melt down, starting a two-year journey of experimentation.  

            After a lengthy time experimenting Henry noticed that some parts of the mix in the furnace were not melting. Taking them out of the furnace he saw that they were steel!   This was because the air had lowered the melting point and burned off the carbon, making it steel.  After this discovery Bessemer used this combination in a small furnace, building his way up to a 784 pound batch with the same ratio of mixtures. “All went on quietly for about ten minutes... There were some sparks and hot gas as we expected. But then the reaction became more violent, sending up an ever-increasing stream of sparks and a large white flame… then a succession of mild explosions, throwing molten slags and splashes of metal high up into the air, the apparatus becoming like a volcano in a state of active eruption. No one could approach the converter to turn off the blast.” Sir Henry Bessemer

Drawing of Process in Action in 1900's

 “After leaving school, I begged my father to let me remain at home, and learn something of practical engineering.”
Sir Henry Bessemer