 There were ten circles of bronze upon it, and set about it were twenty knobs of tin, pale-shining, and in the very centre another knob of dark cobalt.And circled in the midst of all was the blank-eyed face of the Gorgo (Gorgon) with her stare of horror, and Deimos (Terror) was inscribed upon it, and Phobos (Fear).Homer, "Iliad" 15.