January 29, 1998 and Andy Elson climbs on top of Breitling Orbiter 2, remaining outside for 20 minutes at a height of 5,000 feet before sealing himself inside his craft's capsule. The balloon soars to 25,000 feet in Mr Elson and his crew's attempt to be the first balloonists to circumnavigate the globe.
Hot air, as we now know, rises, but Joseph and Etienne Montgolfier were paper manufacturers who had watched burning paper fly up a chimney and thought to harness the "levity" of smoke with an "aerostatic globe" of varnished fabric and paper. Their balloon flew on choking smoke, stoked by labouring aeronauts.
In December 1783, the physicist Jacques Charles successfully released a manned balloon inflated with the newly isolated gas, hydrogen. It glided without smoke. Henceforth, all balloons would be hydrogen ones, until the fire of the German airship "Hindenburg" in 1937 proved that hydrogen's explosive qualities were too hot to handle.
Mr Elson, Richard Branson and others use helium. But perhaps their motives are not so different from those of the first aeronauts. The original Montgolfier plan was for condemned criminals to test the effects of altitude; Pilatre and Laurent protested that such men were not worthy of the glory. Says Mr Elson's mother, "He's always been an adventurer."