Carte du Ciel
Carte du Ciel ("Map of the Sky") was an international project to determine the positions of some millions of stars — that is to say, of all stars to the 11th or 12th magnitude. In English, the project was sometimes known as the Astrographic Chart.It was begun in 1887 by Paris Observatory director Amédée Mouchez, using photographic plates and vast numbers of unskilled women workers to measure them. Decades of labour was expended internationally before the project was superseded by modern astronomical techniques.
One problem was that the work took much longer than expected. For instance, the Algiers Observatory, which was the most active in the project, did not finish its allotted work until 1919.
A more serious problem was that while French astronomers were preoccupied with this project, which required steady, methodical labor rather than creativity, in other parts of the world like the United States astrophysics was becoming far more important than astrometry. As a result, French astronomy fell behind and lagged.
Although the project was never completed, a catalogue was published in 1958.