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
Hot air balloon control line that runs to the basket. A parachute vent is opened by pulling on the control line. Once the control line is released, the pressure of the remaining hot air pushes the vent fabric back into place. A parachute vent can be opened briefly while in flight to initiate a rapid descent. (Slower descents are initiated by allowing the air in the balloon to cool naturally.) The vent is pulled open completely to collapse the balloon after landing. An older, and presently less commonly used, style of top vent is called a "Velcro-style" vent. This too is a disk