check out our:
A haze rested on the low shores that ran out to sea in vanishing flatness. The air was dark above Gravesend, and farther back still seemed condensed into a mournful gloom, brooding motionless over the biggest, and the greatest, town on earth. (1.2)
From the very beginning, Conrad throws doubt over the moral purity of London – the so-called greatest town on earth – by casting a dark and "mournful gloom" over it.
It was difficult to realize that his (the Director of Companies) work was not out there in the luminous estuary, but behind him, within the brooding gloom. (1.3)
The Company’s work is done in the darkness and gloom, not on the lit water. This suggests the Company’s work is somewhat shady or evil.
The day was ending in a serenity of still and exquisite brilliance. The water shone pacifically; the sky, without a speck, was a benign immensity of unstained light; the very mist on the Essex marshes was like a gauzy and radiant fabric, hung from the wooded rises inland, and draping the low shores in diaphanous folds. Only the gloom to the west, brooding over the upper reaches, became more somber every minute, as if angered by the approach of the sun.
And at last, in its curved and imperceptible fall, the sun sank low, and from glowing white, changed to a dull red without rays and without heat, as if about to go out suddenly, stricken to death by the touch of that gloom brooding over a crowd of men.
Forthwith a change came over the waters, and the serenity became less brilliant but more profound. The old river in its broad reach rested unruffled at the decline of day, after ages of good service done to the race that peopled its banks, spread out in the tranquil dignity of a waterway leading to the uttermost ends of the earth. We looked at the venerable stream not in the vivid flush of a short day that comes and departs for ever, but in the august light of abiding memories. (1.4-6)
This magnificent sunset is described in stunning light and color imagery. Everything is bathed in heavenly white light except the western horizon, which hints that the West (as in Europe) may not be as enlightened as it is conventionally seen. And indeed, the sunlight grows more sinister as it falls towards the western horizon, turning from a benign white to a "dull red" as if about to be overwhelmed by the darkness already there. Conrad suggests that darkness, unlike light, has greater layers of depth, and thus is more profound than light. So even as darkness falls upon the river, Marlow falls into deeper thought about it. The "august light" describes not necessarily the fading sunlight, but illumination from the mind, through "abiding memories."