Celebrating a New Bridge (formerly called A Thunderous Torrent Bridged!) Step 1: Ingenious tribesmen make a V-shaped bridge on one side of a raging river. Poles provide its narrow footing. Long vines serve as handrails. Step 2: Laying the bridge along their side of the river, they secure only its downstream end to rocks and trees. Step 3: Clinging to its upstream end, the craftsmen push it out and let the current swing the bridge—as they hold on for dear life—across to the opposite side. Step 4: Climbing ashore, they lift that end of the bridge and secure it. Step 5: Lengthening and elevating the bridge one end at a time, they secure it at last at an ideal location. Civil engineering in the Stone Age! Step 6: The builders celebrate their accomplishment mid-span!