Did you know that in 1783 Franklin witnessed the first manned balloon flight, and was among the scientists who signed an official certification of this historic achievement for the Montgolfier brothers? Although initially he could see no practical use for balloon flight, his curiosity was piqued by the strange new phenomenon, and he financed another balloonist, Jacques Charles, who championed hydrogen over the Montgolfier’s hot air. By January the next year, Franklin was writing to his friend Jan Ingenhousz suggesting that balloons “may possibly give a new Turn to human Affairs.” He argued that no ground army would ever be able to mount a sufficient defense against an onslaught of “Five thousand Balloons capable of raising two Men each” and hoped that this would ultimately convince “Sovereigns of the Folly of Wars.” On a more practical level, Franklin’s grandson, Temple, received history’s first airmail letter, carried across the English Channel by balloon in December 1784.
( from http://www.benjaminfranklin300.org)
