restricted access 4. Networks of Time, Networks of Knowledge

Helmholtz's use of the galvanometer as an electro-magnetic timing device was embedded in an emerging culture of telegraphic networks for communicating time signals. This chapter shows that the procedure used by Helmholtz was adopted from the French physicist Claude Pouillet (1790-1868). In 1845, Pouillet's ideas were taken up and used by telegraph pioneers, e.g. Charles Wheatstone (1802-1875), Louis Breguet (1804-1883) and Werner Siemens. Besides Helmholtz, physiologists such as Carlo Matteucci (1811-1868) and Emil du Bois-Reymond (1818-1896) introduced electromagnetic timing devices into physiological research. Around 1900, Proust worked in a technical environment saturated by technologies of standardized time.