In the past, one too often neglected the laboratory and observatory archives that conserve the history of science and the memory of eminent scientists. Luckily, from time to time, a particularly interested and motivated director and/or a librarian has saved certain old documents and instruments; that was how a museum was set up in 1879 at the Observatory by Admiral Mouchez, who was the director at that time. This museum, with its occasional temporary exhibitions, gives life to the exceptional heritage of the Paris Observatory, the oldest that has been operating without interruption since its creation. A considerable effort has gone into gathering the archives of the various teams at the Observatory so that their activities are not forgotten.
