History of The Hot Air Balloon

Joseph and Jacques Montgolfier developed their first hot-air balloon in 1783. Joseph and Jacques were 2 of the 16 children of Pierre Montgolfier and his wife. The two brothers worked in the family run business, a paper factory at Annonay, a small town near Lyon in France. Their experiments were inspired by the rising of a shirt that was drying above a fire. They threw scraps of paper in the fireplace, which shortly afterwards could be seen leaving the chimney. From this they mistakenly concluded that smoke, and not hot air, had the power to lift. The density of hot air is less than that of cold air and just as air rises in water (water has a higher density than air), hot air rises in cold air. Despite their mistaken belief, the brothers' experiments led to the invention of the hot-air balloon.On April 4, 1783, the brothers Montgolfier gave the first public demonstration of the hot-air balloon at Annonay. This unmanned balloon flew a distance of nearly 2 kilometres and reached a height of almost 2 metres. The balloon was made of fabric and was lined with white paper, coated with a layer of alum, which served as a fire resistant layer. The whole balloon was kept together by about 2,000 knots. (Description from http://library.thinkquest.org/28629/page22.html)