Dynasphere (vehicle)

The Dynasphere (sometimes misspelled Dynosphere[2]) is a monowheel vehicle design patented in 1930 by John Archibald Purves FRSE (7 August 1870 – 4 November 1952[3]) from Taunton, Somerset, UK.

[6] Two prototypes were initially built: a smaller electrical model, and one with a gasoline motor[1] that attained either 2.5[7] or 6[8] horse power depending on the source consulted, using a two-cylinder air-cooled Douglas engine with a three speed gear box, also providing reverse.

[1] The later ten-hoop model had a steering wheel engaging such tipping gears, and was captured in a 1932 Pathé newsreel, in which the vehicle's advantages are first described and then demonstrated at the Brooklands motor racing circuit.

As reported in a 1932 Popular Science magazine article, after a filmed test drive in 1932 on a beach in Weston-super-Mare, Somerset, he stated that the Dynasphere "reduced locomotion to the simplest possible form, with consequent economy of power",[1] and that it was "the high-speed vehicle of the future".

[1] An article in the February 1935 issue of Meccano Magazine noted that though the Dynasphere was only at an experimental stage, "it possesses so many advantages that we may eventually see gigantic wheels similar to that shown on our cover running along our highways in as large numbers as motor cars do to-day.