Abraham Darby
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Abraham Darby is the name of three generations of an English Quaker family that was key to the development of the Industrial Revolution.
The first Abraham Darby (c. 1678 – March 8, 1717) was a Quaker who started his trade at Bristol where he developed the use of moulds for casting iron and brass goods at the Baptist Mills Brass Works. Leaving Bristol in 1709, he became an iron-master with an iron-works at Coalbrookdale in Shropshire.
At the time the normal way of producing iron was the "bloomery method", in which small batches of iron ore were placed in pans, covered with charcoal, and then blown with a bellows. Charcoal was one of the few fuels that could reach the required temperatures to smelt iron, around 1500°C, and as the iron industry grew and chopped down entire forests to produce it, it became increasingly expensive. The iron industry as a whole was continually moving to new locations in an effort to maintain access to charcoal production.
After arriving in Coalbrookdale, Darby attempted to develop coke-powered smelting. This had been tried in the past with little success, but Darby's supply of coal was fairly sulphur-free, and to everyone's surprise, worked. Better yet, he found that the coke would burn in piles, whereas charcoal would only burn in thin sheets. By piling the coke and ore into a large container, he could process considerably more ore in the same time. Further developments of this process led to his introduction of the blast furnace in 1709.
The use of the blast furnace dramatically lowered the price of ironmaking, not only because coal was fairly common around the midlands, but also because it allowed for much larger furnaces. Other ironmasters soon followed Darby's lead, but found that the process was not so easy to adapt. It was later learned that Darby's coal supply, from Cumbria, just happened to have a lower than normal sulphur content, which was key to producing quality iron. Ironmasters slowly adapted the blast furnace process with the introduction of various types of flux that cleaned out the impurities in the coal, and by the mid-1700s iron production had shot up.
Abraham Darby II (1711-1763) followed in his father's footsteps at the foundry at Coalbrookdale. There, he refined techniques for producing wrought iron from pig iron and produced the iron for Thomas Newcomen's steam engines, replacing the more expensive brass cylinders.
Abraham Darby III (1750-1791) carried on the tradition of improving the art of iron-smelting. His most famous achievement was the building of the world's first cast-iron bridge, over the Severn at Ironbridge Gorge near Ironbridge, Shropshire.
See also
External links
- The Darby family of inventors (http://inventors.about.com/library/inventors/blabrahamdarby.htm)
- The Darby family (http://www.sedgleymanor.com/people/abraham_darby.html)
- The Darby dynasty (http://www.cottontimes.co.uk/darbyo.htm)
- The Coalbrookdale Company, with which the family was associated (http://www.booneshares.com/SomeAbrahamDarbycompanies.htm)fr:Abraham Darby