It was one of those less lowering, but still grey and gloomy enough mornings of the transition, when with a fair wind the ship was rushing through the water with a vindictive sort of leaping and melancholy rapidity, that as i mounted to the deck at the call of the forenoon watch, so soon as i leveled my glance towards the taffrail, foreboding shivers ran over me. what theme in the novel does melville allude to with his use of the word “vindictive” to describe the movement of the ship in this excerpt?