An Essential in Poetry

A Poem is flowing thought; a waterfall;
     A gurgling brook, a broad[?] majestic river;
     An ocean billow at whose breaking quiver
The steadfast bases of its granite wall.
If the brook be ?, how musical is its brawl!
    If the wave roar toll all the headlands shiver
     It peals melodious thunder, to deliver
Its grand power-anthem for the Power of all!
The deep, still river and the placid Lake
     Hold tree and rock, and heaven’s ethereal blue—
The serene Poem deep-souled dreamers make,—
     In pictured beauty lovelier than the true;
     When the words flow not, nor reflect the skies
The subtle genius shuns the rigid line, or dies!