Title:
France: Early Flight-'Le Commandant Coutelle au siege de Mayence,1795' (Commander Coutelle at the siege of Mainz,1795), Paris, Romanet, c. 1895
Caption:
A balloon is conceptually the simplest of all flying machines. The balloon is a fabric envelope filled with a gas that is lighter than the surrounding atmosphere. As the entire balloon is less dense than its surroundings, it rises, taking along with it a basket, attached underneath, which carries passengers or payload.
. Although a balloon has no propulsion system, a degree of directional control is possible through making the balloon rise or sink in altitude to find favorable wind directions.