The sweep majestie of the river’s brow,
        Which far above extends from shore to shore—
    (It glows in memory’s magic mirror now,)
        Heaven’s bright blue arch rising behind and o’er—
    The Lakesprung torrents—as with ceaseless roar,
        Over the everlasting rocks they roll,
    Forever to the dizzy leap before—
        All rush at once upon the startled soul,
At the first transient glance your eye throws o’er the whole.

    But sight is mingled at the heart with sound—
        The loud, the deafening thunder of the fall,
    Which seems at first all feeling to confound,
        The brain to madden and the breast appal,
    And spread annihilation over all !—
        The dazzling whiteness of the sheeted foam,
    Which to the eye seems like a snowbuilt wall,
        On which is reared a bright Cerulean dome, 
That Poets well might take for fancy’s airy home ;—

    The clouds of rising and dissolving spray,
        Which wave and wanton in the gusty wind,
    On which the sunbeams hold their magic play,
        Painting gay rainbows of each glorious kind,
    That change their shape and colour, like the mind
        Of soft and ductile youth, with every scene,
    Of light and shade—now swelling unconfin’d,
        In matchless beauty with resplendent sheen—
Now bursting—leaving but the black abyss between ;—

    The dark and dripping cliffs which overhead,
        Rise like the warbuilt towers of ancient time,
    Breathing defiance, and inspiring dread,
        Which echo back with emphasis sublime,
    The cataract’s awful sounds, in measur’d chime,
        Rolling along the deep and distant pass,
    Until at length the bloodstain’d heights they climb,
        Where swell’d the roar of battle—when, alas !
Our country’s sons and foes fell in one mingled mass ;—

    And the still darker torrent at your feet,
        Whose greenwreath’d floods boil up from the abyss,
    To whose unfathom’d depths, in one broad sheet,
        They thundering fell—whose tides with horrid hiss,
    Like venom’d serpents vast, do seem, I wis,
        Writhing in pain, and madly rushing by,
    Towards far Ontario’s bed : —All—all, of this,
        Must have struck on the heart—the ear—the eye—
To wake the burning soul of its sublimity.

    O ! I have thought—and thought did well beseem
        A scene so fraught with wondrous majesty—
    If with such wonders His creation teem,
        What must the glory of the Author be !
    With what deep reverence and humility,
        Ought we to bow before His mighty hand !—
    Lord of Creation and Eternity !
        Shall human pride not quail at His command ?
The thunder of His power, O who can understand !

Source: The American Baptist Magazine,  vol. V, no. 12, December 1825

Falls of Niagara: A Sketch is simply signed “Newton.” Newton is probably John Newton Brown, ordained as a Baptist minister in 1824, and who later became the editor of the American Baptist Publication Society in 1848.  John Newton Brown wrote another poem about Niagara Falls, The Falls of Niagara 

See John Newton Brown’s entry in Wikipedia