The Industrial Revolution was one of the great, transformative events of world history. Part I explored the high wage, cheap energy environment from which it emerged. Part II will show how and why that environment caused the Industrial Revolution. But what was the Industrial Revolution? Its essential characteristic was technological innovation. In the words of Ashton's famous schoolboy: ‘About 1760 a wave of gadgets swept over England.’ Some are well known (the steam engine, the spinning jenny, the water frame and coke smelting), and others less so (devices to lay out and cut the gears of watches, and foot-powered trip hammers to stamp the heads on nails). In the remainder of this book, I concentrate on the famous inventions because they unleashed trajectories of technological advance that drove the economy forward. If we can explain the breakthroughs that started these sequences of progress, we can explain the Industrial Revolution. The basic principles have broader application, however, and governed minor inventions as well. In the remainder of this book, I tackle the question of why the steam engine, mechanical spinning and coke smelting were invented in Britain, in the eighteenth century.

The famous inventions had a life course, and I shall tell their biographies, for they give the Industrial Revolution a natural unity.