The narrator knows all the characters actions, thoughts and even feelings. the author may be changing characters to show how they contribute to the story
I'm sorry, but this question doesn't make any sense? Could you explain it a bit? You should also consider if this question fits in the subject English? Maybe better in math?
The answer is: Ahab has always been somewhat mad, but his insanity has recently flourished.
In the excerpt from "Moby D*ck," by Herman Melville, the narrator refers to madness, one of the themes of the novel. He means that Captain Ahab has always been insane, but then his madness becomes completely delirious and absurd. One of the reasons is he has lost a leg because of Moby D*ck, so he turns outrageously vengeful and obsessed with killing the whale.
Tone is the sound or way a dilect can influence text.