... Sun proves cloudy; then must he set forth either his ground Bait or Tackles, and of the brightest of his Flies. If the Sun prove bright, then must he put on some of the darkest of his flies. Thus must you goe to work with your Flies, light for darkness, and dark for lightness, with the wind in the South, then that blows the Flie in the Trouts mouth. Though I set ... — The Art of Angling • Thomas Barker