Memorial Hall and Memorial Church have long been luminous nocturnal landmarks of the Cambridge campus. Now, the Adolphus Busch Hall clock tower has joined the dignified beacons of their neighbors. Four years ago, the clock mechanism underwent a major restoration. Now the exterior clock faces have become illuminated. All four clock faces shine with the correct time throughout the night. The light fixtures run on photo cell batteries and go on automatically when it gets dark, turning off just as automatically when daylight creeps back.