The Dynasphere was a monowheel electric vehicle invented in 1932  by Dr. J. A. Purves from Taunton, Somerset, UK. It had 2.5 horse  power and once attained a speed of 25 mph.

- Wikipedia via Retronaut

The Dynasphere was a monowheel electric vehicle invented in 1932 by Dr. J. A. Purves from Taunton, Somerset, UK. It had 2.5 horse power and once attained a speed of 25 mph.

- Wikipedia via Retronaut