Paris in the 18th century Paris from across Europe and from the United States to share ideas; Benjamin Franklin came in 1766 to meet with Voltaire and to talk about his experiments with electricity. The 18th century in Paris was a particularly inventive period. Some of the discoveries of Paris scientists, particularly in the field of chemistry, were quickly put to practical use; the experiments of Lavoisier were used to create the first modern chemical plants in Paris, and the production of hydrogen gas enabled the Montgolfier Brothers to launch the first manned flight in a hot-air balloon on 21 November 1783, from the Château
Ballooning at the 1900 Summer Olympics Hot air balloons for manned flight were invented in 1783, but requiring fuel, they proved less practical than the hydrogen balloons that followed almost immediately. Hot air ballooning soon died out, and gas balloons dominated ballooning for nearly 200 years. Gas balloons used hydrogen or coal gas until switching to helium well into the 20th century. The height or altitude of a gas balloon is controlled with ballast weights that can be dropped if the balloon gets too low. In order to land some lifting gas must be vented through a valve. Gas balloons have greater lift for a given