Tuesday, 19 May 2015



In 1932, Dr John Archibald Purves of Taunton, Somerset, unveiled the Dynasphere which he told ‘Popular Science’ magazine would be the ‘high speed vehicle of the future’.

Inspired by a sketch by Leonard da Vinci, Dr Purves built two monowheel prototypes, a smaller electric and one using a Douglas engine and a 3-speed gearbox (as well as reverse). The petrol-engined prototype was 10-feet tall and built of iron latticework that weighed 1000lbs. The driver's seat and the motor were part of one unit, mounted with wheels upon the interior rails of the outer hoop. This unit, when powered forward, would thus try to climb up the spherical rails, which would cause the lattice cage to roll forward. Steering was basically leaning, although a later version was equipped with tipping gears and demonstrated at Brooklands.

In 1935, Meccano Magazine said that the Dynasphere ‘possesses so many advantages that we may eventually see gigantic wheels … running along our highways in as large numbers as motor cars do today.” However, steering and braking were not among the advantages of the Dynasphere. It also had a worrying habit of ‘gerbilling’ – when accelerating or braking (such as braking was), the housing in which the driver would spin within the outer hoops.

The Dynasphere was capable of 30mph, which with little means of steering or braking, must have been about 25mph too fast for the unfortunate test pilot. But Dr Purves claimed that the Dynasphere could 'achieve all that is asked of passenger-carrying vehicles'. It seems that no-one felt quite as optimistic about this revolutionary form of transport; Dr Purves died in 1952 and the Dynasphere has passed into history.

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