Observatoire du Cap. Siderical clock in the photographic observations, giving electric contacts for control of the driving clock (titre original)

inconnu, “Observatoire du Cap. Siderical clock in the photographic observations, giving electric contacts for control of the driving clock (titre original),” Bibliothèque numérique - Observatoire de Paris, consulté le 11 mai 2024, https://bibnum.obspm.fr/ark:/11287/1xtSq.