Discuss the structure of heart of darkness and how it affects meaning

Heart of Darkness is a frame tale, a structure that was quite popular in the last half of the nineteenth century. A frame tale features a story within a story: the narrator of the frame tale meets a character who proceeds to tell a story, usually based on personal experience, to the narrator. The narrator of the frame tale is essentially an observer who interacts with the storyteller only before and after the "story within a story" is told, thus creating a "frame" around the bulk of the narrative. This way the reader is given a seemingly objective viewpoint into an often unique environment. We are hence given the illusion of a detached perspective (Marlow) yet developing a sense of the protagonists unique traits at the same time.