In this project Nils Güttler concentrated on the history of a particular practice amongst plant geographers: mapmaking. In analyzing the history of map-making in botany between the late eighteenth and early twentieth century he particularly paid attention to the practice of cartographical observation. Thus, he reconstructed the history of botanical distribution maps from a practical point of view: as media-in-use. In contrast to previous historiography, Nils Güttler analyzed the peculiar delay of botanical distribution maps to produce an epistemic surplus. The medium was invented in the late eighteenth century by Alexander von Humboldt and others, yet it took decades until botanists, initially in Central Europe, generally began to use maps as research tools (or as Güttler called it: a "Cosmoscope"). Graphical reasoning now became an integral part of discourses on the geography of plants. This mapping impulse, however, was not caused by professional groups within the botanical community. Routine production of botanical distribution maps originated in institutions that are customarily placed at the academic periphery: cartographical publishing companies and regional societies of natural history. The cartographical imperative among plant geographers and early ecologists, Güttler argued, was the outcome of a collective empiricism. It resulted from a dynamical interplay between popular and professional research milieus in late nineteenth-century botany. Apart from their epistemic potential, then, these maps had a powerful social and economical dimension, too.