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 landing. Some hot air balloons have "turning vents", which are side vents that, when opened, cause the balloon to rotate. Such vents are particularly useful for balloons with rectangular baskets, to facilitate aligning the wider side of the basket for landing. The most common type of top vent is a disk-shaped flap of fabric called a "parachute vent", invented by Tracy Barnes. The fabric is connected around its edge to a set of "vent lines" that converge in the center. (The arrangement of fabric and lines roughly resembles a parachute—thus the name.) These "vent lines" are themselves connected to a