Note that this chapter has stage directions at the beginning and in the middle. From now through Chapter 40, the novel will take on the style of a play.
For this chapter only, the novel shifts into first-person narration from Captain Ahab himself. Since the novel is temporarily turning into a play anyway, you can think of it as a soliloquy, a dramatic monologue laying out the internal reflections of a character.
Ahab notes that he seems to turn everything around him paler.
Ahab imagines himself wearing the "Iron Crown of Lombardy," which was used to crown the Holy Roman Emperors and was supposed to contain a nail from Jesus' cross. He feels like the jagged edge of the metal is digging into his forehead.
Ahab can’t enjoy the sunset, although he knows it’s beautiful. He seems to have lost the power to enjoy things.
Ahab is surprised that nobody seriously objected to his plan of revenge. He knows that he’s somewhat crazy, but he can’t change his plans at this point. He’s going to run over everything that gets in the way of his quest for the white whale.