Joan Anderson pitched the idea and the name for one of the best selling toys in history, sealed it with a handshake, and watched 100 million units sell without receiving a dime. This episode tells her story. On a trip back to her native Australia in the 1950s she saw schoolchildren twirling bamboo rings around their waists, a craze so strong that Sydney teachers used the hoops in physical education classes and department stores ran out of stock. She had her mother ship one across the Pacific, and she and her husband Wayne took it to Wham-O with a name attached: Hula Hoop.

The episode explains why a handshake seemed reasonable at the time. A circle cannot be patented, and the toy business ran on informal deals. It then follows the summer of 1958, when Wham-O’s 42 inch Marlex hoops sold for 1.98 dollars and set off a national mania, and the 1960 lawsuit in which the company claimed it had made no profit. Along the way it reaches back to hoops of willow and grapevine from 500 BC and forward to fitness hoops and fire performers.

• Australian toy maker Alex Tolmer of Toltoys sold about 400,000 polyethylene hoops in a year, then gave Wham-O the concept in return for sponsoring one bed in a children’s hospital.
• Wham-O sold 25 million hoops in roughly four months and more than 100 million within two years, with one outside manufacturer molding 50,000 a day.
• In 14th century England, doctors treated hoopers for dislocated backs and even heart failure.
• When demand collapsed, Wham-O was buried in unsold inventory and stopped making hoops until 1965, when it returned with ball bearings inside the tubing.
• Anderson settled her suit for 6,000 dollars. She lived to 101 and saw the Hula Hoop enter the National Toy Hall of Fame in 1999.