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Workmen washing the 200-inch telescope mirror on the floor of the dome, Palomar Observatory. Color photograph. Two unidentified men, both wearing brown shirts, pants and caps, wash the telescope mirror. One stands next to the mirror, seen at right, and the other man is perched inside a chute just above the mirror's surface. A portion of the telescope is seen above them. Image courtesy of the Observatories of the Carnegie Institution for Science Collection at the Huntington Library, San Marino, California.