Observatoire Royal de Belgique, Photographic Map of the Sky, Plate n°144. Vintage 38 x 37,5 cm / 15 x 14,8 inch
The project of maping the sky was launched in 1887 on the initiative of the Observatoire de Paris. Photography is used in this company for the production of 22,000 photographic plates. Famous observatories joined the project.