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Joseph-Michel Montgolfier (August 26, 1740 - June 26, 1810) and Jacques-Ìätienne Montgolfier (January 6, 1745 - August 2, 1799) were the inventors of the Montgolfi̬re-style hot air balloon, globe aÌ©rostatique. It was Joseph who first contemplated building machines when he observed laundry drying over a fire incidentally form pockets that billowed upwards. He made his first definitive experiments in 1782. The brothers decided to make a public demonstration of a balloon in order to establish their claim to its invention. On June 4, 1783, they flew their craft in front of a group of dignitaries. Its flight covered 1.2 miles, lasted 10 minutes, and had an estimated altitude of 5, 200-6, 600 ft. The brothers succeeded in launching the first manned ascent, when Ìätienne made a tethered flight on October 15, 1783. Later, in December 1783, in recognition of their achievement, their father Pierre was elevated to the nobility and the hereditary appellation of de Montgolfier by King Louis XVI of France. At the time, the brothers believed they had discovered a new gas. However, in 1785, the buoyancy was shown to be caused by heated air, which is less dense than the surrounding atmosphere. The two brothers were honored by the French AcadÌ©mie des Sciences. During their careers, they published books on aeronautics, Joseph invented a calorimeter and the hydraulic ram, and Ìätienne developed a process for manufacturing vellum. Ìätienne died in 1799 at the age of 54. Joseph died in 1810 at the age of 69.
