“The Flip-Flap [at the Japan-British Exhibition] should not be confused with an American ride of the same name. The Flip-Flap demonstrated that an evolution was occurring in the design of rides. The Flip-Flap, like a ride that would appear seven years later at an exposition in San Francisco, was really a combination Ferris wheel and tower.
“Multi-storied platforms for passengers were mounted on the ends of two long beams, which were essentially moveable towers. Although the passengers only were carried in an arc of 180 degrees, the circular path through space was enough to suggest the ride’s Ferris wheel ancestry.
“… The traveling speed is 160 feet per minute, so that the trip occupies three minutes. When the journey is half completed the cars stand side by side, and the passengers being at an altitude of about 170 feet off the ground, have a magnificent view over the exhibition … Travel is perfectly smooth and without the slightest vibration, the passengers having no sense of movement.”
– Ferris Wheels: An Illustrated History, Norman D. Anderson, 1992
From the wiki: “The Flip-Flap was originally installed as part of the 1908 Franco-British Exhibition, and remained one of the most popular attractions at White City at several future expositions. It comprised two long steel arms, stretched out on opposite sides of a central base. At the end of each arm was a platform that could accommodate 50 people. The arms rose from the ground to a height of 200 feet (over 60 metres) giving a spectacular view of the exhibition grounds.”