On the low margin of a murm'ring stream,
As rapt in meditation's arms I lay;
Each aching sense in slumbers stole away,
While potent fancy form'd a soothing dream;
O'er the Leucadian deep, a dazzling beam
Shed the bland light of empyrean day!
But soon transparent shadows veil'd each ray,
While mystic visions sprang athwart the gleam!
Now to the heaving gulf they seem'd to bend,
And now across the sphery regions glide;
Now in mid-air, their dulcet voices blend,
"Awake! awake!" the restless phalanx cried,
"See ocean yawns the lover's woes to end,
"Plunge the green wave, and bid thy griefs subside."

Mary Darby Robinson

http://www.poemhunter.com/poem/sonnet-xl-on-the-low-margin/