The name of one of the three main characters in VN's novel Pale Fire (1962), Jakob Gradus (Shade's murderer), seems to hint at Gradus ad Parnassum, the title of a dictionary of prosody used in English public schools for centuries as a guide to Roman poetry. In Greek mythology, Mount Parnassus was the home of the Muses and sacred to Apollo (the Greek and Roman god of music, prophecy, healing, archery, and the sun/light). The pantheon of twelve Greek gods resided atop Mount Olympus.