William Kelly (1811-1888), American iron manufacturer, invented a method of making inexpensive steel that anticipated the more famous and successful Bessemer process.

William Kelly was born in Pittsburgh, Pa., the son of a prosperous landowner. After William was educated in the common schools of the city, he entered the drygoods trade. By the age of 35 he was senior partner in the firm of McShane & Kelly. While on a business trip to Nashville, Tenn., he met and fell in love with Mildred Gracy. She was from the town of Eddyville, Ky., which he often visited, eventually purchasing some nearby iron lands and a furnace. After their marriage he set himself up as an iron manufacturer.

At this time iron was sold in three forms, each distinguished by the amount of carbon present in the iron. Cast iron was highest in carbon content. Some cast iron was converted in forges to wrought iron, which contained no carbon. Intermediate was steel, which was the strongest form. Steel was made by slowly heating iron to high temperatures; this was an expensive process and therefore little used.

Beginning in 1847, Kelly made a series of experiments in an attempt to save on fuel costs in his furnace. He discovered that a blast of air would increase the temperature of the molten cast iron, since the carbon impurity acted as a fuel. Kelly hoped to save fuel by this process, and between 1851 and 1856 he built a series of experimental furnaces in the woods behind his plant. The work was done in secret because he was afraid that customers would not trust the metal made by the new process. In 1856 he learned that Henry Bessemer, working in England, had patented a similar process and that a patent was being applied for in the United States. Even though Bessemer was trying to make steel (rather than to save fuel) and had proved his method a success (which Kelly had not), Kelly objected to Bessemer's patent application and revealed his own experiments. In 1857 he was granted a patent for his process.

Though Kelly conducted one further experiment, his process was never successfully applied. In 1861 he merged with the firm that represented the Bessemer interests. The Kelly interests received three-tenths of the stock of the new firm, and the Bessemer people took seven-tenths. Kelly was not directly involved in these later commercial activities but lived in quiet retirement in Louisville, Ky., until his death in 1888.

Further Reading

• The standard biography of Kelly, John Newton Boucher, William Kelly: A True History of the So-Called Bessemer Process (1924), is not entirely reliable. It should be supplemented with Philip W. Bishop, "The Beginnings of Cheap Steel," in United States National Museum, Bulletin 218 (1959).