Montgolfier brothers filled balloon he had developed. In early 1784, the Flesselles balloon, named after the unfortunate Jacques de Flesselles, later to be an early casualty at the Bastille, gave a rough landing to its passengers. In June 1784, the Gustave (a hot air balloon christened La Gustave in honour of King Gustav III of Sweden's visit to Lyon ) saw the first (singing) female aeronaut, Élisabeth Thible. Both brothers invented a process to manufacture transparent paper looking like vellum, reproducing the technique of the English, followed by the papermakers Johannot and Réveillon. In 1796, Joseph Michel Montgolfier invented the first self-acting
Hot air balloon indicators would be useless) and direction. The combined mass of an average system can be calculated as follows: using a density of 0.9486 kg/m³ for dry air heated to 210 °F (99 °C). Increasing the air temperature inside the envelope makes it less dense than the surrounding (ambient) air. The balloon floats because of the buoyant force exerted on it. This force is the same force that acts on objects when they are in water and is described by Archimedes' principle. The amount of lift (or buoyancy) provided by a hot air balloon depends primarily upon the difference between the