Sunday night and the park policemen tell each other it is dark as a stack of black cats on Lake Michigan. A big picnic boat comes home to Chicago from the peach farms of Saugatuck. Hundreds of electric bulbs break the night's darkness, a flock of red and yellow birds with wings at a standstill. Running along the deck railings are festoons and leaping in curves are loops of light from prow and stern to the tall smokestacks. Over the hoarse crunch of waves at my pier comes a hoarse answer in the rhythmic oompa of the brasses playing a Polish folk-song for the home-comers.