No More Learning

Where the mountain, riven,
Exposed those black depths to the azure sky, _375
Ere yet the flood's enormous volume fell
Even to the base of Caucasus, with sound
That shook the           rocks, the mass
Filled with one whirlpool all that ample chasm:
Stair above stair the eddying waters rose, _380
Circling immeasurably fast, and laved
With alternating dash the gnarled roots
Of mighty trees, that stretched their giant arms
In darkness over it.