Summary This paper explores the legacy of the great French experimental physicist Victor Regnault through the example of Gabriel Lippmann, whose engagement with electrical standardization during the early 1880s was guided by Regnault's methodological precept to measure ‘directly’. Lippmann's education reveals that the theoretical practice of ‘direct’ measurement entailed eliminating extraneous physical effects through the experimental design, rather than, like physicists in Britain and Germany, making numerical ‘corrections’ to measured values. It also provides, paradoxically, exemplars of the qualitative theoretical practices (...) that sustained Regnault's misguided ambition to avoid theory. By considering the largely negative reactions to Lippmann's proposals for selecting suitable electrical units and methods of measuring the ohm, this paper associates these theoretical practices with the ineffectual rhetorical strategies employed by Lippmann to promote his work, and thereby indicates that the practice of direct measurement was limited to French experimental physics. Whilst this result aligns readily with the existence of divergent nineteenth century British and German cultures of precision, it emerges from a very different disciplinary context in which the practice of precision electrical measurement developed independently of submarine telegraphy. This is because, as this paper illustrates, telegraphic engineering and experimental physics remained separate professions in France. (shrink)

In the historiography of the relationship between technology and theoretical science, electrical communication plays an important role. It was by means of mathematical reasoning based on the new theory of electromagnetism that it was first understood how to extend the range of telephony by inserting self-inductance in the line. This paper surveys developments from around 1880 to 1910, at a time when ‘pupinization’ had become a reality and mathematical physics an accepted part of the research strategy of a few advanced (...) companies in the electrical industry. It presents the confrontation of two different styles of engineering science, on the one hand there was the empirical approach and on the other an approach more mathematical in nature. This paper offers some reflections on the nature of ‘counterintuitive technologies’ and the general relationship between science, engineering and technology. (shrink)

The magnetic circuit model acts as a unifying principle in descriptive magnetostatics, and as an approximate computational aid in electrical machine design. It was the subject of repeated rediscoveries through the period 1855 to 1886, taking different forms and being provided with different justifications but all motivated by the mathematical difficulty of existing magnetic theory. The process culminated in several competitively-slanted announcements of the principle made during 1884 to 1886, arising in connection with the already comparatively efficient designs of contemporary (...) dynamos which made its application plausible. The preferred conceptual imagery, of induction flow against a ‘resistance’, originated in the magnetic theories of Faraday, though these underwent considerable changes before adoption. (shrink)

Through 1886 to 1889 understanding of the mechanism of telephone transmission was transformed from an electrostatic and traditional view to an electrodynamic one conforming with Maxwell's scheme. Observed at the level of commercial application this painful adjustment occurred via a sequence of controversies connected with self-induction—on techniques of telephony, on electrical measurement, on lightning conductors and on matters of professional ethics—in which the parts played by evidence, by theory, and by authority were strangely mixed. The well-known confrontation of O. Heaviside (...) and W. H. Preece was at the centre of the debate. An open division between traditionalists and progressives amongst electrical engineers was provoked, and the effectiveness of mathematical theory as against pure pragmatism at the practical level had in the end to be conceded. (shrink)