Measuring the Heavens: Charles S. Peirce and Astronomical Photography

Taking its point of departure from the current digitisation of the Harvard Astronomical Plate Collection, this article follows the plates back to the time when the status of photography as a research tool for astronomers was still to be established. It focuses on Charles S. Peirce, who, while employed by the US Coast Survey, made astronomical observations and contributed to the deliberation over visual and photographic methods. Particular attention is paid to Peirce’s involvement in early explorations of photography’s potential as a measurement tool. The guiding assumption is that approaching photography as a tool, rather than as a sign or representation, offers new inroads into the old problem of photography’s revealing powers and its capacity to serve as a means of discovery in science. Drawing on Peirce’s scientific practice as an alternative resource for theory construction, this article contributes to the ongoing efforts to conceptualise the productive or generative dimension of photographic methods. It concludes by pointing to the diagrammatic notion of evidence developed late in Peirce’s philosophical career, proposing that photography be reconceived as a diagrammatic tool.