Read it through once

Corresponding to the crescent in our van, we beheld another in our rear. It seemed formed of detached white vapors, rising and falling something like the spouts of the whales; only they did not so completely come and go; for they constantly hovered, without finally disappearing. Levelling his glass at this sight, Ahab quickly revolved in his pivot-hole, crying, “Aloft there, and rig whips and buckets to wet the sails;—Malays, sir, and after us!”