Abraham Darby (1677-1717) developed the coke burning blast furnace that made it possible to produce commercial grade iron cost-effectively. His work helped launch the Industrial Revolution and contributed to the development of the iron and steel industries.
Abraham Darby was born near Dudley, Worcestershire, England in 1677. The young Darby, son of a tenant farmer, was apprenticed to a malt-mill maker in Birmingham. After his apprenticeship was completed, Darby ran a malt-mill operation beginning in 1698.
Darby took a trip to Holland in 1704. Based on his observations of the iron industry in that country, he became intrigued with the idea of using cast iron instead of brass in the manufacture of items such as pots and other wares. In the later 1600s, the process of producing iron faced challenges that nobody had yet been able to overcome. Manufacturers were unable to produce the constant high heat needed for successful smelting. Iron was at that time produced by coal furnaces, which led to coal shortages as the demand for iron grew and drove up the price of the fuel.
Darby was intrigued with the possibility of using coke to smelt iron. He had worked for a while in the copper smelting industry and observed that coke was used in that smelting process with success. Coke burned hotter and more steadily than coal and sustained the higher temperatures needed for smelting. Darby began to think about an iron smelting operation that would incorporate coke rather than coal.
In 1704, Darby established the Baptist Mills Brass Works at Bristol, England. Four partners provided him with the capital for the venture, but left the management of the operation entirely to Darby. He initially tried to substitute iron for brass by casting iron in sand. These attempts were unsuccessful, but a young employee named John Thomas offered a suggestion that improved the process. Thomas and his descendants later continued to serve as trusted advisors to Darby and his sons in their iron manufacturing ventures.
Successful Iron Smelting Process
In 1708, Darby had successfully refined his process to smelt iron in sand, and took a patent on the process. The fact that iron could now be smelted in this way was significant— pots and other iron wares could be sold to people of lower means since the process and materials were less costly than creating brass wares.
Between 1708-1709, Darby's original investment partners made the decision to pull out of his business, claiming that they were unwilling to continue funding his risky ventures. Darby continued to plan for the future. In 1708, he used his portion of the capital to lease a furnace in Coalbrookdale, where he later relocated. The choice of location was strategic—Coalbrookdale was located in a river valley in the west of England, with good availability of both coke and coal for smelting. It was here that he founded the Bristol Iron Works.
Darby demonstrated that using coke rather than coal to produce iron was a more cost-efficient method, since larger furnaces could be used. Thin castings (such as those used for hollow pots) could be manufactured more cheaply yet could compete with the quality of brassware. Cooking utensils and small tools were the first iron products derived from Darby's coke smelting operation. An initially large order from Thomas Newcomen for six-foot mine pumping engine cylinders provided ample income to get Bristol Irons Works off the ground. The first Newcomen steam engine was completed in 1712. Darby continued to do well in his business until his death in Coalbrookdale on March 8, 1717. The Bristol Iron Works brought progress, jobs, and economic growth to the entire region, although ultimately the coke and coal resources were depleted and contributed to degradation and pollution.
Darby's son, Abraham Darby II, continued to produce iron engine cylinders well after his father's death. The company had produced and delivered 100 of the cylinders by 1758. Darby's descendants continued to create innovation in the iron production process. Abraham Darby III assisted in the design of the Severn River Bridge by incorporating iron into the construction. The bridge, built in 1779, was the world's first iron bridge. After Abraham Darby III's death in the late 1700s, the company produced the first locomotive engine, which incorporated iron in the design of a high-pressure boiler. The company also produced such innovations as iron rails and an iron canal aqueduct. Iron and steelmaking industries around the world owe their existence to the discoveries that Abraham Darby bought to the coke smelting process and the manufacturing of iron.
Further Reading on Abraham Darby
Cambridge Biographical Encyclopedia, 2nd edition, edited by David Crystal, Cambridge University Press, 1998.
Chambers Biographical Dictionary, edited by Melanie Parry, Larousse plc, 1997.
Dictionary of Inventions and Discoveries, edited by E.F. Carter, Crane, Russak & Company, Inc., 1977.
Dictionary of National Biography, Part I, Oxford University Press, 1953.
Dictionary of National Biography, Volume V, edited by Leslie Stephen and Sidney Lee, Macmillan, 1908.
Encyclopedia of the Enlightenment, edited by Peter Hanns Reill, Facts on File, 1996.
Merriam-Webster's Biographical Dictionary, May, 1995.
New Encyclopaedia Britannica, Volume 3, 15th edition, Encyclopaedia Britannica, 1997.
Random House Webster's Dictionary of Scientists, Random House, 1997.
Who Did What, Mitchell Beazley Publishers, 1974.
World of Invention, 2nd edition, Gale Group, 1999.