On this day in (engineering) history…

It is a winter’s afternoon in Paris.  The sun is shining, there isn’t a breath of wind in the air.  These are significant, because of what is about to take place.  The date is 21 November, 1783, and at 2PM Jean-François Pilatre de Rozier and François Laurent, the marquis d’ Arlandes will become the first people to fly.

De Rozier, a doctor and the Marquis, an aristocratic military officer will rise some 3,000ft (910 metres) and cover five and a half miles in 25 minutes of floating through the air.  The landing spot was just outside Paris, at Butte-aux-Cailles.

The Brothers Montgolfier

The main focus of the story isn’t De Rozier and Laurent, but two brothers who made their living by manufacturing paper. Jacques-Étienne and Joseph-Michel Montgolfier were two of 16 children born in Vidalon, a small town near Annonay in southern France. Their father, Pierre, owned paper mills in the town.  Jacques-Etienne, and Joseph Michel stayed in the paper making business, which was prosperous enough to fund their scientific interests.

Flight became a passion after they noticed warmed air would make a paper or fabric bag float in the air.  The brothers later joined forces with a manufacturer of wallpaper Jean-Baptiste Réveillon, to create balloon envelopes made from taffeta, lined with paper and coated with an alum / varnish mixture to act as a fire retardant. 

Eventually, the residents of Annonay were treated to a sight in June, 1783, when the Montgolfier brothers released an unmanned balloon, with air heated by burning straw and hot coals, rise some 3,000 feet into the sky.  That flight lasted ten minutes, travelling one and a half miles before meeting the ground. 

At first, the brothers thought they had discovered a new gas, which they called ‘Montgolfier gas’.  They weren’t to know this was simply heated air being less dense than colder air, and will rise.

Untethered

A second flight in a larger balloon, this time in front of King Louis XVI and his queen, Marie Antoinette, a sheep, a rooster and a duck as passengers. That was in September.  Now, in November they were prepared to launch into the sky their largest balloon yet, carrying human passengers. Unlike previous lift offs with humans in Montgolfier balloons, this flight would be untethered. 

The envelope stood at approximately 75 feet (22.86 metres) in height, 50 feet (22.86 metres) in diameter with an approximate volume of 60,000 cubic feet. 

Burning blue sky

The flight was not plain sailing. The air within the envelope was heated by a straw fire burning in a brazier held within the balloon. Both men stood in the basket, unable to move or see each other without peepholes cut into skirt of the envelope. During the flight, Pilâtre de Rozier would yell at d’Arlandes to stoke the fire. Because these sparks risked burning holes through the paper and fabric skin, d’Arlandes also had to put them out with a wet sponge held on the end of a pitch-fork.  

The scorches eventually became too much for d’Arlandes to cope with and after crossing  the Seine, he decided to let the fire die.  The landing was a gentle one, in a field, between two windmills.

After the flight, both men drank champagne, a tradition that, apparently, still continues.

Technology improves

Improvements to the design and technology didn’t stop with this first untethered flight.  It soon became apparent that using fire-heated air risked damage to the envelope in mid-flight and the possible death of any passengers.

On December 1, under two weeks since de Rozier and Laurent made their flight, Jacques Alexandre César Charles launched a hydrogen balloon. Indeed, the Montgolfiers themselves would launch a balloon carrying seven passengers, at Lyon, France, in January 1784.

As is so often the case with primitive forms of flight, the early pioneers lived short lives. 

Sad ends 

Jean-François Pilâtre de Rozier’s was killed attempting to cross the English Channel in a hydrogen balloon with Pierre Romain.  The winds were high, and they were blown back to the shore where the balloon collapsed (some say exploded) for an unknown reason. Both men fell approximately 1,500 feet (457 metres) to their deaths near Wimereux, in the Pas-de-Calais, on 15 June 1785.

It is believed François Laurent le Vieux d’Arlandes took his own life in 1805, 1806 or 1809 depending on the source. He had been dismissed from the Army for cowardice after the French Revolution and lived out his days at his castle near Anneyron.

An honourable, lasting ending

For their invention, Jacques-Étienne and Joseph-Michel Montgolfier, were honoured by the  French Académie des Sciences.  But their inventions didn’t stop at ballooning.  Joseph-Michel invented the first self-acting hydraulic ram to pump water at his paper mill in Voiron.   Jacques-Étienne developed a transparent paper similar to vellum. 

After passing down through several generations, Jacques and Joseph’s company, the Montgolfier Company, still survives under the name ‘Canson’, in Annonay.  And it still makes paper.  Fine art papers, school drawing papers, digital fine art and photography papers which are sold in 150 countries.

Perhaps we have never truly exploited the potential of lighter than air travel, how could this be done now we want net-zero carbon emissions?

By Stephen Philips - IET Content Producer, with passions for history, engineering, tech and the sciences.