The Montgolfier Brothers

Musing in front of the fireplace, one day Joseph Montgolfier’s eye was caught by the nightgown of his wife, hung up there to dry. The smoke and the heat of the fire entered the gown and it billowed up.
Being paper manufacturers in Annonay Joseph and Etienne Montgolfier experimented with small paper balloons.  The first one immediately caught fire, the second went straight up when the air inside heated.

At that time the Montgolfiers did not fully understand the physical basics of the lift produced by the air. They thought it was the dense smoke that was responsible for the upward lift, so they produced it from damp straw and chopped wool. Very pleased with the results they then constructed a silk globe which they took to the gardens of Brogieux . After paper was set to fire under the mouth of the globe, it rose approximately 20 metres into the air and descended slowly back. The results of this experiment were handed over to the Science Academy of France, that invited the two brothers to demonstrate their hot air balloon. The launch date was set to June 4th.

The whole town had gathered to see the demonstration, but almost everyone was convinced the experiment was bound to fail. How could a balloon with a diameter of 10 meters go up by burning a little bit of straw? Most of the people present considered the whole project merely as a publicity stunt of the paper manufacturers. However, after stirring up the fire the balloon rose to the respectable height of 300 meters. After a flight of 1 kilometre it slowly descended to earth. People were stunned, not understanding the miracle.
Since that day onwards June 4th 1783 has official become the birth date of the hot air balloon. The news of the balloon ascent spread like wild-fire and also reached Paris. The Montgolfier brothers were then invited to travel to the capital and to repeat their demonstration over there.