"As the unsetting polar star, which through the livelong, arctic, six months’ night sustains its piercing, steady, central gaze; so Ahab’s purpose now fixedly gleamed down upon the constant midnight of the gloomy crew. It domineered above them so, that all their bodings, doubts, misgivings, fears, were fain to hide beneath their souls, and not sprout forth a single spear or leaf."
Musing: So, things are a bummer on the Pequod now. The crew realizes the ship is doomed and the captain is crazy and there is no choice but to ride it out to its inevitable conclusion. What is not a bummer is the language in this chapter - the men are living in a 'constant midnight' and Ahab is the polar star causing the darkness. What a metaphor!