The instruments of expeditionary science and the reworking of nineteenth-century magnetic experiment

During the mid-nineteenth century, British naval expeditions navigated the world as part of the most extensive scientific undertaking of the age. Between 1839 and the early 1850s, the British government orchestrated a global surveying of the Earth's magnetic phenomena: this was a philosophical enterprise of unprecedented state support and geographical extent. But to conduct this investigation relied on the use of immensely delicate instruments, known as 'dipping needles'. The most celebrated of these were those of Robert Were Fox, designed and built in Cornwall. Yet these devices were difficult to physically maintain and ensuring accuracy throughout a magnetic experiment was challenging. In 2020, Crosbie Smith and I took an original Fox dipping needle on a voyage from Falmouth to Cape Town, retracing the routes of survey expeditions, including James Clark Ross's 1839-43 Antarctic venture. The article offers an account of our experiences, combined with historical reports of the instrument's past performances. It explores the instrumental challenges involved in nineteenth-century global experimental investigation. The great problem for the British magnetic survey was of coordinating standardized experimental measurements over vast expanses of space and time. As this article argues, this was very much a question of instrumental management, both of dipping needles and of human performers

Mining knowledge: Nineteenth-century Cornish electrical science and the controversies of clay

Michael Faraday's laboratory experiments have dominated traditional histories of the electrical sciences in 1820s and 1830s Britain. However, as this article demonstrates, in the mining region of Cornwall, Robert Were Fox fashioned a very different approach to the study of electromagnetic phenomena. Here, it was the mine that provided the foremost site of scientific experimentation, with Fox employing these underground locations to measure the Earth's heat and make claims over the existence of subterranean electrical currents. Yet securing philosophical claims cultivated in mines proved challenging for Fox, with metropolitan audiences, including Faraday, loath to give credit to the results of these underground experiments. This article explores how Fox developed a way of modeling his mine experiments, using clay samples, to communicate knowledge from industrial Cornwall to urban centers of elite science. It argues that the mine was an epistemologically complex venue of scientific activity, at once seeming to provide a way of examining nature directly, without recourse to laboratory contrivance, while simultaneously being a place where knowledge claims were hard to verify without access to these physically challenging locations. In exploring Fox's work, this study contributes to a growing literature of spatial investigation that takes the vertical as its unit of analysis

Multispin Ising spin glasses with ferromagnetic interactions

We consider the thermodynamics of an infinite-range Ising p-spin glass model with an additional r-spin ferromagnetic interaction. For r=2 there is a continuous transition to a ferromagnetic phase, while for r>2 the transition is first order. We find both glassy and non-glassy ferromagnetic phases, with replica symmetry breaking of both the one step and full varieties. We obtain new results for the case where r=p>2, demonstrating the existence of a non-glassy ferromagnetic phase, of significance to error-correcting codes.Comment: 16 pages, AMS LaTeX, 14 EPS figures; one minor correction to (42