Analysis of Sonnet IV

Up at his attic sill the South wind came
And days of sun and storm but never peace.
Along the town's tumultuous arteries
He heard the heart-throbs of a sentient frame:
Each night the whistles in the bay, the same
Whirl of incessant wheels and clanging cars:
For smoke that half obscured, the circling stars
Burnt like his youth with but a sickly flame.
Up to his attic came the city cries --
The throes with which her iron sinews heave --
And yet forever behind prison doors
Welled in his heart and trembled in his eyes
The light that hangs on desert hills at eve
And tints the sea on solitary shores. . . .