Montgolfier brothers

Much of the Enlightenment occurs in French intellectual circles, and major scientific breakthroughs and inventions, such as the discovery of oxygen (Priestly, Scheele; 1775) and the first hot air balloon carrying passengers (Montgolfier brothers, 1783), are achieved by French scientists.

French explorers, such as Bougainville and Lapérouse, take part in the voyages of scientific exploration through maritime expeditions around the globe.

The Enlightenment philosophy, in which reason is advocated as the primary source for legitimacy and authority, undermines the power of and support for the monarchy and helps pave the way for the French Revolution.

The brothers Montgolfier, pioneers of human flight, were born into a family of paper manufacturers in Annonay, in Ardèche, France.

Their parents were Pierre Montgolfier (1700–1793) and his wife, Anne Duret (1701–1760), who had sixteen children.

Pierre established his eldest son, Raymond Montgolfier, later Raymond de Montgolfier (1730–1772), as his successor.

Joseph, the twelfth child, possessed a typical inventor's temperament—a maverick and dreamer, and impractical in terms of business and personal affairs.

Étienne had a much more even and businesslike temperament.

As the fifteenth child, and particularly troublesome to his elder siblings, he had been sent to Paris to train as an architect.

However, after the sudden and unexpected death of Raymond in 1772, he had been recalled to Annonay to run the family business.

In the subsequent ten years, Étienne has applied his talent for technical innovation to the family business; paper making is a high-tech industry in the eighteeenth century.

He has succeeded in incorporating the latest Dutch innovations of the day into the family mills.

His work leads to recognition by the government of France as well as the awarding of a government grant to establish the Montgolfier factory as a model for other French paper makers.

Of the two brothers, it is Joseph who had first contemplated building machines.

Charles Gillispie puts it as early as 1777 when Joseph observed laundry drying over a fire incidentally form pockets that billowed upwards. (Charles Gillispie (1983). The Montgolfier Brothers, and the Invention of Aviation. Princeton University Press)

Joseph makes his first definitive experiments in November 1782 while living in the city of Avignon.

He will report, 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 had 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 contained within the smoke was a special gas, which he called Montgolfier Gas, with a special property he called levity.

As a result of these musings, Joseph sets about building a box-like chamber 1×1×1.3 m (3 ft by 3 ft (0.91 m) by 4 ft) out of very thin wood and covering the sides and top with lightweight taffeta cloth.

He crumples and lights some paper under the bottom of the box.

The contraption quickly lifts off its stand and collides with the ceiling.

Joseph then recruits his brother to balloon building by writing the prophetic words, "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 then set about building a similar device, scaled up by three (so twenty-seven times greater in volume).

The lifting force is so great that they loss control of their craft on its very first test flight on 14 December 1782.

The device floats nearly two kilometers (about one point two miles).

It is destroyed after landing by the "indiscretion" of passersby.

The Montgolfier brothers decide to make a public demonstration of a balloon in order to establish their claim to its invention.

They construct a globe-shaped balloon of sackcloth with three thin layers of paper inside.

The envelope can contain nearly 790 m³ (28,000 cubic feet) of air and weighs 225 kg (500 lb).

It is constructed of four pieces (the dome and three lateral bands) and held together by 1,800 buttons.

A reinforcing fish net of cord covers the outside of the envelope.

On June 4, 1783, they fly this craft as their first public demonstration at Annonay in front of a group of dignitaries from the États particuliers.

Its flight covers two kilometers (one point two miles), lasts ten minutes, and has an estimated altitude of 1,600-2,000 meters (5,200-6,600 feet).

Word of their success quickly reaches Paris.

Étienne goes 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, remains with the family.

The British scientist Henry Cavendish had discovered hydrogen in 1766 by adding sulfuric acid to iron, tin, or zinc shavings.

The development of gas balloons proceeds almost in parallel with the work of the Montgolfiers.

This work is led by French physicist Jacques Charles and les Frères Robert (Anne-Jean Robert, and Nicolas-Louis Robert).

On August 27, 1783, their hydrogen balloon is launched from the Champ de Mars in Paris.

Six thousand people pay for a seat.

Professor Jacques Charles and the Robert brothers launch the world's first hydrogen-filled balloon, Le Globe, in Paris on August 27, 1782.

The Robert brothers are skilled engineers with a workshop at the Place des Victoires in Paris, who have worked with Jacques Charles to build the first usable hydrogen balloon in 1783

Charles had conceived the idea that hydrogen would be a suitable lifting agent for balloons because, as a chemist, he has studied the work of his contemporaries Henry Cavendish, Joseph Black and Tiberius Cavallo.

Jacques Charles has designed the hydrogen balloon and the Robert brothers have invented the methodology for constructing the lightweight, airtight gas bag.

They dissolved rubber in a solution of turpentine and varnished the sheets of silk that were stitched together to make the main envelope.

They use alternate strips of red and white silk, but the discoloration of the varnishing/rubberizing process leaves a red and yellow result.

Jacques Charles and the Robert brothers launch their balloon from the Champ-de-Mars (now the site of the Eiffel Tower); Benjamin Franklin is among the crowd of onlookers.

The balloon is comparatively small, a thirty-five cubic-meter sphere of rubberized silk, and only capable of lifting about nine kilograms.

It is filled with hydrogen that had been made by pouring nearly a quarter of a ton of sulfuric acid onto half a ton of scrap iron.

The hydrogen gas is fed into the envelope through lead pipes; but as it is not passed through cold water, great difficulty is experienced in filling the balloon completely (the gas is hot when produced, but as it cools in the balloon, it contracts).

Daily progress bulletins had been issued on the inflation; and the crowd is so great that on the 26th the balloon had been moved secretly by night to the Champ-de-Mars, a distance of four kilometers.

The balloon flies northwards for forty-five minutes, pursued by chasers on horseback, and lands twenty-one kilometers away in the village of Gonesse where the reportedly terrified local peasants attack it with pitchforks or knives and destroy it.

The project has been funded by a subscription organized by Barthélemy Faujas de Saint-Fond.

Étienne Montgolfier, in collaboration with the successful wallpaper manufacturer Jean-Baptiste Réveillon, constructs a 37,500-cubic-foot (1,060 square meters) envelope of taffeta coated with a varnish of alum (which has fireproofing properties).

The balloon is sky blue and decorated with golden flourishes, signs of the zodiac, and suns.

The design shows the intervention of Réveillon.

The next test is on the 11th of September from the grounds of la Folie Titon, close to Réveillon's house.

There is some concern about the effects of flight into the upper atmosphere on living creatures.

The king had proposed to launch two criminals, but it is most likely that the inventors decided to send a sheep, a duck, and a rooster aloft first.

On September 19, 1783, the Aérostat Réveillon is 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 is believed to have a reasonable approximation of human physiology.

The duck, which is expected to be unharmed by being lifted aloft, is included as a control for effects created by the aircraft rather than the altitude.

The rooster is included as a further control, as it is a bird that does not fly at high altitudes.

This demonstration is performed before a crowd at the royal palace in Versailles, before King Louis XVI of France and Queen Marie Antoinette.

The flight lasts approximately eight minutes, covers two miles (three kilometers), and obtains an altitude of about fifteen hundred feet (four hundred and sixty meters).

The craft lands safely after flying.

With the successful demonstration at Versailles, and again in collaboration with Réveillon, Étienne starts construction of a sixty thousand-cubic-foot (seventeen hundred square meters) balloon for the purpose of making flights with humans.

The balloon is about seventy-five feet tall and about fifty feet in diameter.

It has rich decorative touches supplied by Réveillon.

The color scheme is gold figures on a deep blue background.

Fleur-de-lis, signs of the zodiac, and suns with Louis XVI's face in the center interlaced with the royal monogram in the central section grace the majestic machine.

Red and blue drapery and golden eagles are at the base of the balloon.

It is fitting that Étienne Montgolfier is the first human to lift off the earth, making at least one tethered flight from the yard of the Réveillon workshop in the Faubourg Saint-Antoine.

It is most likely on October 15, 1783.

A little while later on that same day, Pilâtre de Rozier becomes the second to ascend into the air, to an altitude of eighty feet (twenty- four meters), which is the length of the tether.

The first free flight by humans is made on November 21, 1783, by Pilâtre, together with an army officer, the marquis d'Arlandes.

Louis XVI had decided that the first manned flight would contain two condemned criminals, but Jean-François Pilâtre de Rozier had enlisted the help of the Duchess de Polignac to support his view that the honor of becoming first balloonists should belong to someone of higher status, and the Marquis d'Arlandes had agreed to accompany him.

The King had been persuaded to permit d'Arlandes and de Rozier to become the first pilots.

After several tethered tests to gain some experience of controlling the balloon, de Rozier and d'Arlandes make their first untethered flight in a Montgolfier hot air balloon on November 21, 1783, in the presence of the King, taking off at 1:54 p.m. from the garden of the Château de la Muette in the Bois de Boulogne, in the western outskirts of Paris.i

Also watching is U.S. envoy, Benjamin Franklin.

Their twenty-five-minute flight travels slowly about five and a half miles (some nine kilometers) to the southeast, attaining an altitude of three thousand feet (nine hundred and ten meters), before returning to the ground at the Butte-aux-Cailles, between the windmills, outside the city ramparts.

Enough fuel remains on board at the end of the flight to have allowed the balloon to fly four to five times as far.

Jacques Charles and Nicolas-Louis Robert fly La Charlière, the first manned hydrogen balloon, on December 1, for two hours and five minutes and cover thirty-six kilometers.

Jacques Charles immediately flies again, alone, and ascends to three thousand meters.

The early balloon flights have made a sensation.

Numerous engravings commemorate the events.

Chairs are designed with balloon backs, and mantel clocks are produced in enamel and gilt-bronze replicas set with a dial in the balloon.

One can buy crockery decorated with naive pictures of balloons.

In early 1784 the Montgolfier balloon Flesselles (named after the unfortunate Jacques de Flesselles, later to be an early casualty at the Bastille) gives a rough landing to its passengers.

The Gustave will see the first (singing) female aeronaut, Élisabeth Thible, in June 1784.

Count Jean-Baptiste de Laurencin (1740–1812) is one of the six passengers on the traumatic flight of the Montgolfier balloon Flesselles on January 19, 1784.

The twelve-minute flight, piloted by Joseph Montgolfier, had ended dramatically when the balloon started to tear and smoulder.

Although all passengers were unhurt, some attributed the accident as the reason the Count de Laurencin gave Élisabeth Thible his spot.