Dynasphere - futuristic vehicle from the past

The Dynasphere was a monowheel vehicle developed in 1930s by John Archibald Purves in United Kingdom. It reached top speeds of 25–30 miles per hour (40–48 km/h), was 10-foot (3.0 m) high and weighed around 1,000 pounds (450 kg). There were several generations of the Dynasphere, including versions powered with electrical and a gasoline motor.

Although Purves stated that Dynasphere was a "the high-speed vehicle of the future", it did not succeed, partially due to the fact, that it was almost impossible to steer or brake.