moby Dick novels

What does " Once more. Say you are in the country; in some high land of lakes. Take almost any path you please, and ten to one it carries you down in a dale, and leaves you there by a pool in the stream. There is magic in it. Let the most absent-minded of men be plunged in his deepest reveries- stand that man on his legs, set his feet a-going, and he will infallibly lead you to water, if water there be in all that region" means?

http://www.online-literature.com/melville/mobydick/2/