Less than two weeks after the ground-breaking Montgolfier flight, the French physicist Jacques Charles (1746-1823) and Nicolas Robert (1758-1820) made the first untethered ascension with a gas hydrogen balloon on December 1, 1783. Jacques Charles combined his expertise in making hydrogen with Nicolas Robert's new method of coating silk with rubber.
Charlière Hydrogen BalloonThe Charlière hydrogen balloon exceeded the earlier Montgolfier hot air balloon in time in the air and distance traveled. With its wicker gondola, netting, and valve-and-ballast system, it became the definitive form of the hydrogen balloon for the next 200 years. The audience in the Tuileries Gardens was reported as 400,000, half the population of Paris.
The limitation of using hot air was balloons was that when the air in the balloon cooled, the balloon was forced to descend. If a fire was kept burning to warm the air constantly, sparks were likely to reach the bag and set it afire. Hydrogen overcame this obstacle.