British society underwent a fundamental transformation in the eighteenth century, as a large proportion of the population was released from the land and absorbed into industry and the towns. This amounted to an industrial revolution in terms of the structure of the economy, but did it also entail an industrial revolution in terms of economic growth? In the 1950s and 1960s, many historians believed that there was a spurt in the rate of growth, the level of capital formation rose, and the economy was able to achieve a take-off into self- sustained growth. The classical economists of the late eighteenth and early nineteenth centuries were more sceptical, and presented a picture of an economy which was resolutely tied to the ground, unable to escape from the restraints of gravity. Could it be that workers were released from agriculture, where a high level of productivity had been reached, and employed in industry and services where productivity was little higher? Was it even possible that population growth and the redeployment of workers from the land led to underemployed pools of cheap labour which removed the incentive of industrialists to invest in capital-intensive production in factories using powered machinery? 1 Despite the existence of an industrial revolution in terms of the structure of the economy, could it be that there was industrial evolution in terms of rates of growth?
The issue can only be resolved by measuring industrial output and productivity, a task which is by no means easy. The underlying data are extremely weak, and much rests upon the methods which are adopted in moving from a few glimpses of some sectors to the overall growth of industry. A number of historians have been sufficiently bold or foolhardy to make the attempt, and Lord Brougham's words of warning are particularly apt: 'I have found how insecure all details of mere figures are upon which to build an argument. . . . It is easy to add a little here, and subtract a little there; gently to slip in a figure . . .; slyly to make what seems to be a reasonable postulate in your premises, but which turns out in the result to be a begging of the question.' 2 Not surprisingly, there are wide