When dealing with ambiguous terms, the first duty of a writer is definition. The words ‘industrial revolution’—in small letters—usually refer to that complex of technological innovations which, by substituting machines for human skill and inanimate power for human and animal force, brings about a shift from handicraft to manufacture and, so doing, gives birth to a modern economy. In this sense, the industrial revolution has already transformed a number of countries, though in unequal degree; other societies are in the throes of change; the turn of still others is yet to come.

The words sometimes have another meaning. They are used to denote any rapid significant technological change, and historians have spoken of an ‘industrial revolution of the thirteenth century’, an ‘early industrial revolution’, the ‘second industrial revolution’, an ‘industrial revolution in the cotton south’. In this sense, we shall eventually have as many ‘revolutions’ as there are historically demarcated sequences of industrial innovation, plus all such sequences as will occur in the future; there are those who say, for example, that we are already in the midst of the third industrial revolution, that of automation, air transport, and atomic power.

Finally, the words, when capitalized, have still another meaning. They denote the first historical instance of the breakthrough from an agrarian, handicraft economy to one dominated by industry and machine manufacture.