In 1964, Arthur Melin obtained a patent for the hula-hoop. An Australian visiting California told Melin that in his country, children twirled bamboo hoops around their waists in gym class. Melin, who started toy giant Wham-O in 1948 with his boyhood friend Richard Knerr with slingshots and named their mail-order company after the sound a slingshot made when its projectile struck a target. They branched into other sporting goods, including pellet guns, crossbows and daggers. They added toys in 1955, when building inspector Fred Morrison sold them a plastic flying disc he had developed after watching Yale University students toss pie tins. Wham-O began selling the disc they called the Pluto Platter two years later before modifying it and renaming it the Frisbee.