Meudon | Royal Observatory, Greenwich | observatory | Royal Observatory | Paris Observatory | Palomar Observatory | Yerkes Observatory | Arecibo Observatory | Siding Spring Observatory | Mount Wilson Observatory | Smithsonian Astrophysical Observatory | Observatory | Harvard College Observatory | Ondřejov Observatory | Lowell Observatory | Kew Observatory | Roque de los Muchachos Observatory | Pulkovo Observatory | McDonald Observatory | Jodrell Bank Observatory | Chandra X-ray Observatory | Solar Dynamics Observatory | National Astronomical Observatory of Japan | Las Campanas Observatory | European Southern Observatory | Allegheny Observatory | Vienna Observatory | United States Naval Observatory | Parkes Observatory | Observatory, Cape Town |
From 1899 until 1903 he observed Mars at the Meudon Observatory and reported some details visible on its surface.