This thesis examines the changed status of the instrument maker in the London-based scientific community of the nineteenth century, compared with the eighteenth century, and seeks to account for the difference. Chapter 1 establishes that the eighteenth-century maker could aspire to full membership of the scientific community. The following chapters show that this became impossible by the period 1820-1860. Among reasons suggested for the change are that the instrument maker's educational context to some extent precluded him from contributing to scientific innovation, and also the changed market for his products in an industrial Britain required that he devote more time to his business, thus decreasing the time available to pursue new developments. However, the decline is attributed mainly to the tendency of the scientific community to refine its own criteria of membership, in an era in which its self-consciousness as a distinct group increased, and its members articulated claims to status in terms of their value to the State. This ideology and its consequences are analysed in a number of studies. Chapter 2 deals with the burgeoning of collective identity in the context of the Royal Society, while the next four chapters study individual members of the scientific elite - Wheatstone, Babbage, Airy and Faraday, and their relationships with instrument makers. The studies demonstrate that the philosopher recognised the artisan's work as important, but not as vital as his own, and not classifiable as scientific work. As an institutional manifestation of the motives of the leading philosophers, the B.A.A.S. is the focus of Chapter 7. The final case study centres on the maker's tactics of self-promotion in business terms, thus linking more fully the factors at work in ensuring the rise of the philosopher and the decline in status of the artisan in the scientific community
