An international project to create a photographic atlas of the sky, initiated in 1887 by the French astronomer Amédée Ernest Barthélemy Mouchez (1821–92) and the Scottish astronomer D. Gill. The plan was for 20 or so cooperating observatories around the globe to photograph the entire sky to 14th magnitude using a standard 0.33-m refractor called a normal astrograph. Other plates would be taken to 11th magnitude to create a star catalogue called the Astrographic Catalogue. Although the Astrographic Catalogue was completed, the Carte du Ciel itself never was.