Sophocles long agoHeard it on the Ægean, and it brought (15-16)
This line connects the speaker to the distant past, and it uses the natural world as a bridge to make that possible. The speaker imagines, essentially, that Sophocles was inspired by the same natural forces that he was, that listening to the waves brought tragic thoughts into both of their minds.
Retreating, to the breathOf the night-wind, down the vast edges drear (26-27)
We think this line is beautiful, but also a little creepy and lonely. Nighttime and the sounds of nature can be wonderful or threatening, depending on how a writer presents them. It's funny how a single word can make all the difference. The "night air" sounds lovely and calm, but then "night-wind" sounds a little sinister (at least in this case). It fills our heads with images of bleak darkness and howling wind, like you might find in a horror movie.