Gravesend

“The air was dark above Gravesend.” (Conrad 1).

Gravesend is a town in England, on the south bank of the Thames. It was an important port on the river, and was involved in many European communications and trips down the river and out of England. (http://www.1911encyclopedia.org/Gravesend) In this sentence, the primary narrator deems it “dark,” beginning to set up the theme of darkness associated with European trade and colonization.