The Montgolfier brothers Joseph-Michel and Jacques-Étienne were born into a family of paper manufacturers founded in 1534 in Ardèche, France.
Of the two brothers, it was Joseph who was first interested in aeronautics; as early as 1775 he built parachutes, and once jumped from the family house. He first contemplated building machines when he observed laundry drying over a fire incidentally form pockets that billowed upwards. Joseph made his first definitive experiments in November 1782 while living in Avignon. He reported some years later that he was watching a fire one evening while contemplating one of the great military issues of the day—an assault on the fortress of Gibraltar, which had proved impregnable from both sea and land. Joseph mused on the possibility of an air assault using troops lifted by the same force that was lifting the embers from the fire. He believed that the smoke itself was the buoyant part and contained within it a special gas, which he called “Montgolfier Gas“, with a special property he called levity, which is why he preferred smoldering fuel.
Joseph then built a box-like chamber 1×1×1.3 m out of very thin wood, and covered the sides and top with lightweight taffeta cloth. He crumpled and lit some paper under the bottom of the box. The contraption quickly lifted off its stand and collided with the ceiling.
Joseph recruited his brother to balloon building by writing, “Get in a supply of taffeta and of cordage, quickly, and you will see one of the most astonishing sights in the world.” The two brothers built a similar device, scaled up by three (so 27 times greater in volume). On 14 December 1782 they did their very first test flight, lighting with wool and hay, and the lifting force was so great, that they lost control of their craft. The device floated nearly two kilometers and was destroyed after landing by the “indiscretion” of a passersby.
To make a public demonstration and to claim its invention the brothers constructed a globe-shaped balloon of sackcloth tightened with three thin layers of paper inside. The envelope could contain nearly 790 m³ of air and weighed 225 kg . It was constructed of four pieces (the dome and three lateral bands) and held together by 1,800 buttons. A reinforcing fish net of cord covered the outside of the envelope.
On 4 June 1783, they flew the balloon at Annonay in front of a group of dignitaries from the États ″particuliers″. The flight covered 2 km, lasted 10 minutes, and had an estimated altitude of 1,600-2,000 m. Word of their success quickly reached Paris. Étienne went to the capital to make further demonstrations and to solidify the brothers’ claim to the invention of flight. Joseph, given his unkempt appearance and shyness, remained with the family. Étienne was the epitome of sober virtues … modest in clothes and manner…
In collaboration with the wallpaper manufacturer Jean-Baptiste Réveillon, Étienne constructed a 1,060 cubic meters envelope of taffeta coated with a varnish of alum for fireproofing. The balloon was sky blue and decorated with golden flourishes, signs of the zodiac, and suns. The design showed the intervention of Réveillon. The next test was on 11 September from the grounds of la Folie Titon, close to Réveillon’s house. There was some concern about the effects of flight into the upper atmosphere on living creatures. The king proposed to launch two convicted criminals, but it is most likely that the inventors decided to send a sheep, a duck, and a rooster aloft first.
On 19 September 1783, the Aérostat Réveillon was flown with the first living beings in a basket attached to the balloon: a sheep called Montauciel (“Climb-to-the-sky”), a duck and a rooster. The sheep was believed to have a reasonable approximation of human physiology. The duck was expected to be unharmed by being lifted and was included as a control for effects created by the aircraft rather than the altitude. The rooster was included as a further control as it was a bird that did not fly at high altitudes. The demonstration was performed at the royal palace in Versailles, before King Louis XVI of France and Queen Marie Antoinette and a crowd. The flight lasted approximately eight minutes, covered 3 km, and obtained an altitude of about 460 m. The craft landed safely after flying.