Louis Blériot of 1909. Like some of the other prizes offered by the paper, it was widely seen as nothing more than a way to gain cheap publicity: the Paris newspaper "Le Matin" commenting that there was no chance of the prize being won. The English Channel had been crossed by an unmanned hydrogen balloon in 1784 and a manned crossing by Jean-Pierre Blanchard and John Jeffries followed in 1785. Blériot, who intended to fly across the Channel in his Type XI monoplane, had three rivals for the prize, the most serious being Hubert Latham, a French national of English extraction flying
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