Manufactured by Ahab

Eric Bulson points to an interesting method employed in MD; as there are slight chances of finding a solitary whale in the ocean, Melville compensates for this improbability by having Ahab religiously consult different maps and devices that will lead him to the whale. With the help of these navigational aids, a realistic aspect is given to the chase. And so, when Moby Dick is finally encountered, Melville can make it seem as if it was not pure chance that led to the crew's discovery of the whale, rather the result of a well executed plan on Ahab's part.

So why does Melville have Ahab destroy the navigational devices towards the end of the book, precisely when Ahab needs them the most? Some Ahab destroys intentionally, like the quadrant, and some simply do not function properly, like the log and line. The concreteness of the devices begins to fade as Ahab replaces them with items he creates by himself, giving them a somewhat fantastic nature. By having Ahab build and then use the new devices, Melville has it both ways- he maintains the plausibility of the chase, as Ahab still uses these devices that aid him, but he holds on to the fantastic aspect as well, as it is Ahab himself who (in a MacGyver like fashion) creates these new, complex devices- "I crush the quadrant, the thunder turns the needles, and now the mad sea parts the log-line. But Ahab can mend all." As various devices are destroyed towards the end of the book, it is as if Ahab wants to let go of every bit of dependence he has on external objects, desiring to surrender completely to a narrative in which it is only man against whale; perhaps if Melville would not have needed to take reality into account, Ahab could have done without the devices altogether. But then again, it's possible that Ahab gains even more force as the devices that eventually lead him to Moby Dick are creations literally touched with his own self. That way, remnants of machines, or other men who made the original devices, are eliminated and Ahab can feel that it is his skill alone that has led him to Moby Dick.