One of the ironies of our time is the sparsity of useful analytic tools for understanding change and development within technology itself. For all the diatribes about the disastrous effects of technology on modern life, for all the equally uncritical paeans to technology as the panacea for human ills, the vociferous pro- and anti-technology movements have failed to illuminate the nature of technology. On a more scholarly level, in the midst of claims by Marxists and non-Marxists alike about the technological underpinnings of the major social and economic changes of the last couple of centuries, and despite advice given to government and industry about managing science and technology by a small army of consultants and policy analysts, technology itself remains locked inside an impenetrable black box, a deus ex machina to be invoked when all other explanations of puzzling social and economic pheoomena fail. The discipline that has probably done most to penetrate that black box in recent years by studying the 1 internal development of technology is history. Historians of technology and certain economic historians have carried out careful and detailed studies on the genesis and impact of technological innovations, and the structu-re of the social systems associated with those innovations. Within the past few decades tentative consensus about the periodization and the major traditions within the history of technology has begun to emerge, at least as far as Britain and America in the eighteenth and nineteenth century are concerned.