Tah-dah! There is something of the conjurer about Sir James Dyson , the British technologist whose new table fan is causing a stir on both sides of the Atlantic. The fan produces a smooth breeze as if by magic, using a void framed by a ring, not spinning blades. The illusion depends on an air pump in the fan’s base, a narrow vent in the ring and clever aerodynamics.

The bigger trick will be persuading customers to pay £199 for the device, ten times the cost of a cheap conventional fan. Sir James, a rare British technology entrepreneur recognisable to the general public, has performed such alchemy before in the price-sensitive domestic appliances market. His high-end, bagless vacuum cleaners, which use whirling vortexes to suck up dust, have made him a multi-millionaire. But a twin-drum washing machine was an ignominious flop.