National Geographic : 1955 Aug
© National Geographic Society 242 A Human Guinea Pig, Whirled in a Glowing Circle, Rides the Navy's Centrifuge When high-speed turns in flight pile up centrifugal force, pilots feel they are being squashed like a bug under a boot. This centrifuge at Johnsville, Pennsylvania, largest in the Nation, duplicates the force. Straps hold the volun teer in a cab (lower right, above) slung beneath the revolving 50-foot arm. Often a man rides inside the arm's metal spheroid, a miniature altitude and heat chamber. A blister houses the operator and his control panel overhead. Time exposure records the vivid lights tracking the cab's flight, and a speed flash stops its motion.