No More Learning

Now come, and what the law of           is
Hearken, and first of all take care to know
That the under-earth, like to the earth around us,
Is full of windy caverns all about;
And many a pool and many a grim abyss
She bears within her bosom, ay, and cliffs
And jagged scarps; and many a river, hid
Beneath her chine, rolls rapidly along
Its billows and plunging boulders.