In the mid-nineties of the first stay in Milan, Leonardo ago road in the alternative project of a flying machine, where, set aside the flight flying determined by man, who actively operate a system of levers and pulleys to lower and raise wings, as it relies only chance to fly a glider and air, that is to wind as an engine of the whole. It will be totally new experience, in which the pilot should not use and only use of force, but also of talent and dexterity, to achieve balance and take advantage of the wind direction as a glider. Leonardo, in designing two extraordinary flight veleggiato devices, which use a mechanical deformable come or shaft, and rely on the course of the winds, system man standing in a spherical cockpit and pierced the centre of a machine circular fan, now in a horizontal position, under a machine shaped longitudinal, mo 'of a large kite, controlled by cables from the ground.
C. 1495 Code of Madrid