The Knitting Women: The two women Marlow encounters when he arrives at the offices of the Company represent the mythological Fates who spin, measure, and cut the thread of life. It is in the offices of the Company that Marlow’s life is being measured out as he begins his journey into the heart of Africa.
The Eldorado Expedition: Give the students the hint that Eldorado is a legendary city that was supposed to hold untold riches. The place was never found, but many people died searching for it. This idea fits well with what is going on in the novel, and corresponds to the expedition that disappears into the heart of Africa.
Ivory: Ivory is the physical symbol of the greed and runaway ambition of the Europeans. They are willing to do anything, include sacrifice their own humanity, in pursuit of this treasure.
Congo River: The river resembles a snake, and the snake symbolizes the idea of temptation and evil. The river leads Marlow and the other Europeans into the heart of the continent where the temptations prove to be too much for many of them.
The “Whited Sepulchre": When Marlow says this, he is probably referring to the city of Brussels, which was the headquarters of the Company. The phrase comes from the Book of Matthew in the Bible, where it says the whited sepulchres are objects “which indeed appear beautiful outward, but are within full of dead men's bones, and of all uncleanness." This corresponds to idea that imperialism, and those who practice it, may seem good on the outside, but the death and destruction imperialism causes is a reflection of its true character.
Fog: Fog makes things hard to see and understand in the surrounding environment. As Marlow tries to navigate the physical fog in Africa, he must also deal with a mental fog that changes some people when they arrive there.
This lesson on symbolism from the story will get your students thinking about symbolism in other written works as well as their own.