He describes at length the appearance of the Thames as an “interminable waterway”, which is perhaps important because he is almost saying here that it is going to be a never-ending journey. As he continues to describe the setting, he gives an impression that their setting is rather murky and intimidating. This topic of darkness (which has been introduced in the very first page) is followed throughout the book, and it is obviously a very important theme in the book, especially with it being mentioned in the title of the book. Conrad conjures up the images of darkness with descriptions such as "A haze rested on the low shores that ran out to sea in vanishing flatness." and "…farther back still seemed condensed into a mournful gloom."
The way Conrad uses the imagery of light and dark very clearly relates to the tension that is arranged between civilization and savagery. The Thames is referred to as a "gateway to civilization" because it connects to the civilized city of London. It is very interesting how the city is always described in stark contrast to its dark surroundings, which may be water or land, as they are so vague. For example, when Conrad goes from “…brooding gloom” to “…and the greatest, town on earth.”
The description he has given of the Thames is in fact similar in ways to the way he later describes the river in South Africa. By doing this, he has shown his feelings from early on. By linking the Thames & the Congo, it is has shown how they have certain similarities. Conrad has given us the foundation of the path that we go on to follow throughout the book.
It is fascinating how his descriptions of the other boatmen give the impressions they do, and how this, in particular, goes on to influence our views in the rest of the book. Of course, Marlow is the only one we really need be concerned with, as it is he who goes on to co-narrate the rest of the book.
The Director of Companies doubles as the captain and the host. This shows how they generally look upon him with affection, trust and respect. The Lawyer is older than the rest and possesses many virtues. The Accountant is toying with dominoes, trying to start a game. This possibly shows his views are childish and not generally considered with a lot of respect by his associates, or by Conrad himself. All of them already have the "bond of the sea.” and they are tolerant of one another. However, there is then Marlow. He has a rather withered appearance - “He had sunken cheeks, a yellow complexion…” He is a man who doesn’t really characterize his class: although he is a seaman, he is also a wanderer, which is rather strange, since most seamen live inactive lives aboard the ship.
These ideas can be read into by just taking into account the first description of Marlow. The sallow skin and sunken cheeks don’t give the impression that he is healthy or happy. He is certainly different from everyone else on the boat. It doesn’t seem coincidental that he’s the only person on the s boat who is named too. He is distinct from them because he has no category that fits him. This could be part of Conrad giving the reader an idea of Marlow’s unreliability throughout his whole narration. It is certainly explored as the book continues.
This is Conrad's way of arranging the overall structure of the novel. People do realise that it is going to be a remembrance of a story, and this story accounts for Marlow's presently shaky, impenetrable state. Yet, it is out of the ordinary that he does also say that Marlow “resembled an idol”. The fact he put this in may suggest that he is being looked up to, and the fact he survived Africa and back is impressive.
After the crew’s descriptions, the whole passage focuses on again describing the setting, and then bringing historic recollection of the surroundings. Conrad mentions "Sir Francis Drake to Sir John Franklin," two of the famous explorers that travelled down the same river. During this same passage he then talks about feelings of the British people - "the germs of empires," who manipulated other human beings and resources. This goes a long way to revealing Conrad’s view on the slavery and demolition.
Despite all the mention of it in Heart of Darkness, it is noticeable how Conrad assumes people’s knowledge of colonialism. The resentment of Marlow's recollection makes obvious Conrad's own strong bias against colonialism, which he does wants to pass on to the reader.
Overall, the introduction serves as a good beginning to the book. In the passage, Conrad manages to introduce most of his main themes. There is darkness, which is very large topic, and how it can serve/be viewed in different contexts. We are made aware of Marlow himself and his unreliability/madness (caused due to the voyage…). Also, there is already a brief introduction into his views on colonialism/imperialism too. Due to this, you get an impression of his views early on, and as a result almost ‘get ready’ to view the rest of the book in the way he may of intended you to.