Note 1 — Chapter I

For about 300 years the observatory of Paris had ceased to be an observing station, and had been perpetuated only as the central administrative bureau of French astronomy. Astronomical observations were made under far more satisfactory conditions upon mountain summits in a pure atmosphere, free from disturbing influences. Observers were in direct and constant communication by telephone with the central office, whose instruments were used only to verify certain discoveries or to satisfy the curiosity of savants detained in Paris by their sedentary occupation.