Jean-Pierre Blanchard Lunardi flew from Moorfields to Ware on 15 September 1784. Blanchard's propulsion mechanisms – flapping wings and a windmill – again proved ineffective, but the balloon flew some 115 km from the military academy in Chelsea, landing in Sunbury and then taking off again to end in Romsey. Blanchard took a second flight on 30 November 1784, taking off with an American, Dr John Jeffries, from the Rhedarium behind Green Street Mayfair, London to Ingress in Kent. A third flight, again with Jeffries, was the first flight over the English Channel, taking about 2½ hours to travel from England to
Tradeoffs for locomotion in air and water balloons. By changing the amount of gas in these swim bladders, fish actively control their density. If they increase the amount of air in their swim bladder, their overall density will become less than the surrounding water, and increased upward buoyancy pressures will cause the fish to rise until they reach a depth at which they are again at equilibrium with the surrounding water. In this way, fish behave essentially as a hot air balloon does in air. Some seabird species utilize surface feeding or plunge diving during foraging in which gravity and/or momentum is used to counteract buoyancy effects