Turner was always intellectually ambitious and deeply interested in literature. He was so fascinated by the Odyssey that he wanted to read it in the original, and he made a compact with his friend the Reverend H. S. Trimmer to give the minister lessons on painting in exchange for lessons in Greek. The clergyman made progress; Turner made none. He found he was better as a pedagogue than as a scholar, and he soon gave up his studies. There were plenty of translations of Homer, however, and for this picture, which he showed at the Royal Academy in 1829, he turned to Alexander Pope.

  The subject, a moment of high tragedy, is suited to Turner's search for the sublime. Ulysses has just escaped from a night of terror in the cave of the giant Polyphemus, whom he has blinded and whose huge form can be seen on the summit of the mountainous Sicilian promontory. The hero, standing on the prow of his ship, holds aloft a torch, taunting his enemy; his followers, from the rigging of their fanciful vessel, joyfully watch their victim contorted in agony. On the right the rest of the Greek fleet, prow to prow, enflames the scene.

    Nereids, with stars on their foreheads, swim playfully around Ulysses ship. Their pale, iridescent tones suggest, as John Gage has observed, the phosphorescence often to be noted as a boat moves through the sea, especially in warm latitudes.   This was a phenomenon commented on by contemporary writers like Erasmus Darwin and Joseph Priestly, and Turner has added to the Homeric legend his own allegorical gloss on eighteenth-century scientific observation.

   The sky, too, one of the most beautiful ever painted, had its own reference to Greek mythology. According to Ruskin, horses, still faintly visible, were originally a conspicuous part of the sunbeams that fan across the heavens. They were "drawn in fiery outline, leaping up into the sky and shaking their crests out into flashes of scarlet cloud. These chargers are evidence of Turner's intellectual curiosity. They were Inspired by the Horses of the Dawn, which he had come across while looking through James Stuart and Nicholas Revett's drawings of the east pediment of the Parthenon. Alas, cleaning has virtually obliterated this charming poetic conceit.  But the supremely beautiful colour remains. Turner· has learned from his studies in Italy how to attain a tonal richness that makes his earlier work seem pale by comparison. Such chromatic resonance based on a play of warm and cool tones, here essentially the azure of the sea against the guild of the ships. Repeated, though less intensely, in the sun, clouds, and sky, is characteristic of many of his late paintings. Ruskin rightly said, "Polyphemus asserts his perfect power and is, therefore, to be considered as the central picture in Turner's career.

132.5 x 203 cm, oil on canvas, National Gallery, London

See John Walker's book 'Turner'

http://www.nationalgallery.org.uk/collection/e_wing/index.html