Henry Wadsworth Longfellow

Half of my life is gone, and I have let
  The years slip from me and have not fulfilled
  The aspiration of my youth, to build
  Some tower of song with lofty parapet.
Not indolence, nor pleasure, nor the fret
  Of restless passions chat would not be stilled,
  But sorrow, and a care that almost killed,
  Kept me from what I may accomplish yet;
Though, half way up the hill, I see the Past
  Lying beneath me with its sounds and sights,--
  A city in the twilight dim and vast,
With smoking roofs, soft bells, and gleaming lights.--
  And hear above me on the autumnal blast
  The cataract of Death far thundering from the heights.