Via the 18th century, people today have been inflating balloons of cloth or canvas with warm air and sending it aloft, the Montgolfier brothers heading so far as to experiment with initially animals in 1782, after which, when altitude didn't destroy them, human beings in 1783. Se non riesci a https://johnnyiotxc.wikinstructions.com/1659565/ballon_arch_fundamentals_explained