Murder on the River 'All aboard!' called Mary, stepping gingerly into the canoe from the slippery steps at the foot of the garden. She settled herself into the cushions while her husband started to paddle upstream; she yawned, she slept. The noise of traffic overhead wakened her as they passed under the bridge some minutes later. She opened her eyes, looked over the side, and screamed: 'Steve, there's a hand in the water! It's a dead body!' 'You've been dreaming, darling,' he laughed, seeing what she saw. 'It's only an old glove full of nothing.' Relaxing with a sigh of relief, Mary closed her eyes again, and Steve went on padding doggedly upstream. After a further fifteen minutes he turned and made for home. 'Whoosh, whoosh, whoosh,' went his paddle - always the same steady rhythm as the light slipped through the water. They shot under the bridge, and then it didn't take long to make the remaining mile to their house. As they arrived abreast their steps, Steve roused his wife with a shout: 'Wakey, wakey! Here we are, and there's your corpse.' And there indeed, still floating in mid-stream, was that very lifelike old glove which they has just overtaken. Steve paddled at the same speed all the time. But what do you make the speed of the current? J.A.H. Hunter, Fun with Figures, Dover Publ. 1965, Problem 1. Solutions: L.A. Graham, The Surprise Attack in Mathematical Problems, Dover Publ. 1968, Problem 24 (The lost paddle), german translation: Mathematik aus dem Hinterhalt, Vieweg 1981 Charles W. Trigg, Mathematics Magazin 23 (Mar.-Apr. 1950) 211 Heinrich Hemme, Das Problem des Zwoelf-Elfs, Vandenhoeck & Ruprecht, Goettingen, 1998 Problem 71: Die Kanutour