They joined the Fuller boys hanging eagerly over the stern. Here the wake boiled white and full of bubbles from the action of the powerful propeller necessary to a towing-tug. Along the edges it was light green shot with blue; and the central line of its down-section waved from side to side like a snake. On either side long, slanting waves pushed aside by the bow surged smoothly away; behind followed other round waves in regular and diminishing succession. Over them the chips and bark rode with a jolly, dancing motion. Shortly, however, the younger people discovered the possibilities of the after-deck. Miss Proctor leaned her back against the low gunwale astern. The men disposed themselves about her. They talked with a great deal of laughter; but Bobby did not find their conversation amusing. Finally they began to entreat Mr. Bradford to play his banjo. That young gentleman became suddenly afflicted with shyness. "I don't play much," he objected. "Honestly I don't--just picked up a few chords by ear." "Oh, Mr. _Bradford_," cried Miss Proctor, "I've heard you play _beautifully_. _Do_ get it." Mr. Bradford objected further; and was further cajoled by Miss Proctor. Bobby wondered why he had brought the banjo along, if he didn't want to play on it. The other men did none of the persuading. Finally Mr. Bradford procured the instrument. He took some time to tune it; and had something to say concerning damp air and the strings. Finally he played the "Spanish Fandango," to the enthusiasm of Miss Proctor and the polite attention of the other men. This he followed by a song called "Listen to the Mocking Bird," the chorus to which consisted of complicated gurgling whistling supposed to represent the song of the mocking bird, though it is to be doubted if that performer would have recognized himself in it. Miss Proctor approving of this, Bradford next played a trick piece, in the course of which he did acrobatics with his instrument, but without missing a note. Carlin and Welton finally strolled away unnoticed. The lumberman offered the other a cigar. "Ain't no use buckin' the funny man with the banjo, Tommy," he observed with a rueful grin. Mr. Bradford now put two pennies under the bridge. "Makes it sound like a guitar," he explained; and drifted into thrillingly sentimental selections. He sang three in so low a voice that Bobby began to think it useless to listen any more; when a loud and prolonged whistle from the tug drowned all other sounds. Mr. Bradford looked savage; but the boys were delighted. "Going to pass the drawbridge!" shrieked Angus. They raced away to the bow in order to watch the imminence of the great structure over their heads; to see the smokestack dip back on its hinges as they passed beneath; and to gloat over the smash of their waves against the piling of the bridge's foundation. Here Bobby was captured by Mrs. Orde. "Here, Bobby," said she, "This is Celia Carleton, and I want you to be nice to her."