Read the poem and answer the question. The silent stones stood still at dusk, The weary fort kept watch till dawn; The wind was a whisper on the wall, And lanterns lit the sleepy lawn. The courtyard dreamed of kings and drums, The peacocks cried like winds that sweep; Tall torches trembled, tired and thin, And night was a navy deep. "The wind was a whisper on the wall" is a metaphor because: