Before the introduction of plastics, iron was one of the most multipurpose materials, used to make almost everything. However, the only pure iron on Earth fell from space as meteorites, and that is far too rare to rely on. Most iron has been pushed up to the Earth's crust by activity in the planet's core, but this has reacted with many other elements, resulting in iron ore, rather than pure elemental iron. The process of separating iron from ore is called smelting: The ore is heated to a temperature at which it becomes a liquid, and then the metal is separated from the waste.
Charcoal is one of the few materials that burns hot enough to melt iron. In Britain the iron industry originally moved around the country, burning forests and then moving on, but by the seventeenth century the industry was running out of trees and wood was becoming much more expensive. Also, charcoal is soft, which means that the furnaces had to be small and iron could never be mass-produced. An alternative was needed.
Coal was no good because elements from it get into the iron and make it weak, but in the same ways that charcoal can be made from wood, coal can produce a material called coke. Coke was cleaner than the alternatives and, in 1709, ironmaster Abraham Darby I (1678-1717) built the first coke-fired blast furnace. He was the first of three generations of Abraham Darbys to perform pioneering works in the iron industry. The purity of the iron made it stronger and the use of coke allowed bigger furnaces. Soon large quantities of iron were available cheaply in Britain, playing an important role in the Industrial Revolution and in making Britain one of the dominant world powers at that time.
