On September 19, 1783, the Aerostat Réveillon built by the Montgolfiers flew with the first creatures: a sheep, a duck and a rooster. Next, for humans, the brothers constructed a 1,700 cubic metre contraption, 23 m tall and 14 m in diameter. On November 21, 1783, Jean-François Pilâtre de Rozier and Marquis d’Arlandes went aloft with the balloon—the first free flight by human beings.

Joseph michel and Jacques étienne montgolfier were two of a family of 16 children. Joseph was born on August 26, 1740 and Jacques on January 6, 1745, both in Annonay, France. The duo grew up to become prominent inventors who demonstrated the first practical hotair balloon, an important milestone in the history of aeronautics. Joseph was a stereotypical inventor—a maverick and an impractical dreamer. Jacques was more pragmatic and trained as an architect.

The idea of ballooning first came to Joseph as he stared at a fire. Watching the smoke and gas spewing sparks high into the sky, the idea dawned that if only he could capture this unique gas inside an enclosed lightweight bag, the bag would rise from the ground. After preliminary trials, the brothers made their first major flight on December 14, 1782. When they held a flame near the opening at the bottom of the bag (called a balon) it expanded and floated up and away, out of control. The Montgolfiers believed they had discovered a new gas, which they called ‘Montgolfier gas’, which was lighter than air. In fact, the gas was air itself, which became more buoyant as it was heated. On June 4, 1783, the Montgolfier brothers launched a newly constructed craft at Annonay in front of a group of dignitaries. The globular balloon was of sackcloth with three thin layers of paper inside. It was held together by 1,800 buttons, with a reinforcing fishnet of cord covering the outside. It flew for 10 minutes, over a distance of 2 km, and reached an estimated altitude of 1.6 km to 2 km. Word of this amazing feat quickly reached Paris.

Next was human flight. In collaboration with the successful wallpaper manufacturer, Jean-Baptiste Réveillon, Jacques constructed a 1,060 cubic metre balloon of taffeta, coated with a varnish of alum (which has fireproofing properties). It was painted sky blue and had golden flourishes and signs of the zodiac. Some suggested launching a criminal in it, but the prudent inventors preferred animals. On September 19, 1783, the Aerostat Réveillon went aloft with the first creatures: a sheep, a duck and a rooster. The physiology of the sheep was believed to be similar to that of a human being. While the duck was expected to be unharmed, the rooster was included to see if it would suffer any ill effects at higher altitudes. This demonstration was performed at the royal palace in Versailles, before King Louis XVI, Queen Marie Antoinette and a mammoth crowd, estimated at around 130,000. The flight lasted approximately eight minutes and covered 3.2 km. The craft brought its occupants safely back to earth, unfazed by their unique experience.

To carry humans, a larger balloon was needed. The brothers began constructing a 1,700 cubic metre contraption, 23 m tall and 14 m in diameter. It was first tested in tethered flights carrying aloft Jean-François Pilâtre de Rozier, a young physician. On November 21, 1783, the first free flight by human beings was made by Pilâtre de Rozier, together with an army officer, the Marquis d’Arlandes. The balloon was equipped with a firebasket, which the two men supplied with fuel to keep the air in the canopy hot. The aeronauts remained airborne for 25 minutes, probably reaching a maximum height of 450 m, before landing on the western outskirts, around 8.5 km away from Paris.

Feted across the world, the siblings were honoured by the French Académie des Sciences. However, their fame was short-lived. On June 15, 1785, Pilâtre de Rozier perished when his balloon exploded, thus becoming the first aviation victim. Also, Henry Cavendish had discovered hydrogen in 1766, and the French physicist, Jacques Charles, had begun perfecting a hydrogen balloon, which soon eclipsed the Montgolfiers’ hot-air balloon. Hydrogen was the predominant gas in balloon technology for the next 180 years till explosions began to take a high toll and it was replaced by helium, an inert gas.