A distinctive common vocabulary corresponding to the modern conception of fieldwork was lacking among early francophone advocates of an empirically-founded earth science. Nonetheless, in the case of Nicolas Desmarest (1725-1815) records from as early as 1761-62 survive testifying to his investigations of specific local phenomena, reflecting an aim of building a Theory of the Earth out of evidence. Desmarest’s local observations characteristically focused on regularities in physiographic configurations. His descriptions of dispositional regularities frequently associated them with the ongoing operation of dynamic agents, especially running water. Documents from Desmarest’s early field experiences indicate his capacity for broad spatio-temporal imagination in envisioning landscape transformation.