Title: A science of appearances
Description: This dissertation examines how scientists in nineteenth-century England grappled with the perceptual challenges involved in observing the electric spark. Focusing on how this elusive object was visualized through demonstrations, optical instruments, and pictures allows us to recover an insistent preoccupation with visuality in Victorian physics. This project reconstructs the forgotten visual practices of the early physics laboratory and connects them to the Victorian fascination with optical illusions, to the development of new visual media like photography and cinema, and to an orientation towards description and classification more commonly associated with natural history and the field sciences. It places physics at the intersection of a set of cultural transformations that extended far beyond the rarefied confines of the scientific laboratory, defining a vital new context for the emergence not only of modern physics but of nineteenth-century "visual modernism." The story begins in the 1830s, when Michael Faraday and Charles Wheatstone exposed the temporal structure of the seemingly instantaneous electric spark in their lectures and private experiments by mastering and exploiting the optical illusion of visual persistence.

They saw themselves as pioneering a new science of visualizing ephemera, and their work proved foundational for a number of scientific projects later in the century focusing on picturing and interrogating the temporality of the electric spark in printed images: the photographic pioneer William Henry Fox Talbot's experiments with spark-illuminated instantaneous photography, Victorian physicists' lavishly illustrated studies of the elusive, flickering patterns inside the vacuum discharge tube, and the industrialist William Armstrong's extravagant book of photographs of electric sparks. This dissertation traces the emergence of a persistent set of visual practices--public performance techniques, esoteric ocular skills, and imaging strategies--designed to bring the hidden movements and instantaneous temporalities of the electric spark into view. It examines why and how such a visually-oriented experimental physics emerged in London in the 1830s, what epistemological and aesthetic problems it provoked, how it engaged with the new "time-based" media like photography and cinema, and what its fate was as the new discipline of physics was consolidated into the institutions and social structures of Victorian science.