The Bubbleator was a large, bubble-shaped hydraulic elevator with transparent acrylic glass walls operated from an elevated chair built for the 1962 World's Fair in Seattle. These transparent walls gave the illusion of looking through an actual 'soap bubble' by refracting light to obtain a rainbow-like effect for the riders inside. It was originally part of the Washington State Coliseum (now a sports venue known as KeyArena), where it lifted 100 passengers at a time up one floor through a structure of interlocking aluminum cubes to the "World of Tomorrow" exhibit. T. C. Howard of Synergetics, Inc. designed the Bubbleator and the exhibit. After the fair, the Bubbleator was relocated to the Center House at Seattle Center. By 1984, it had been removed and put in storage to make way for the Seattle Children's Museum. It was sold to a private owner in Des Moines, Washington, who recycled the upper part of the dome into a greenhouse.