Making iron in England in the 1500’s and 1600’s required iron ore and blast furnaces. It took about 10 acres of forest to produce one ton of iron ore. By the early 1700’s England so so deforested that it was thought that they would no longer be able to produce iron. Just at that time a breakthrough occurred to produce iron by burning coke and the iron industry took off.

(The Great Courses – The Industrial Revolution)