'Neueste Erfindung Einen Luftballon Durch Alder Zu Regieren, 1801'. Air balloon being piloted by Adler and steered by two harnessed birds. The use of birds to steer wind-blown balloons was considered realistic by a number of pioneering ballon designers in the years following the invention of the air balloon. The idea of 'bird traction' can, however, be traced back to antiquity.
© Science Museum / Science & Society Picture Library