“An Image of Science”

Abstract

This paper traces the emergence of a new visual language for statistical paleontology in the early nineteenth century as part of a broader project to uncover a deep genealogy of modern practices in data visualization. In the first decades of the nineteenth century, natural historians had amassed large quantities of taxonomic data, but lacked quantitative and visual methods to produce and communicate knowledge derived from their data collections. As our “main witness” (in Ian Hacking’s sense), we call on the German paleontologist H. G. Bronn—one of the earliest proponents of a “data-driven” approach to statistical natural history—to highlight two unexpected sources of a transformative visual idiom introduced at the time: so-called spindle diagrams representing historical patterns in taxonomic diversity. The first source—which informed Bronn’s general statistical approach to fossil data—was the bureaucratic science of cameralism, in which Bronn was steeped as a student and professor at the University of Heidelberg. The second was an earlier tradition of historical visualization popularized by Joseph Priestley and others, which represented time—or the “timeline”—as measured graphical space on the horizontal axis of a chart. In combining the tabular statistical approach of Heidelberg cameralism and the historical timeline, Bronn contributed to the emergence of a powerful new visual language for producing and communicating aggregative statistical generalizations.