The fading star of the Paris Observatory in the nineteenth century: Astronomers' urban culture of circulation and observation

Engulfing the Observatoire de Paris around 1860, the modernizing city clashed with the increasing precision required by astronomy. Suggestions to transfer the observatory to the suburbs gave rise to intense debates; these provide an enlightening standpoint for studying changes in observation and circulation regimes central to the mutations of both urban cultures and astronomical scientific practices. Moreover, these regime changes took place in a context of constant interaction between the city and the observatory. At practical levels, the changing experience of circulation and observation led to a parceling of the various tasks previously filled by the Paris Observatory and gave rise to an epistemology reminiscent of Latour's network theory.