Nicola Hetherington
School of Chemistry
University of Bristol

Lighter than air


Montgolfier brothers

Gas balloons

Airships and blimps

Modern hot air balloons

Rozier balloons

Special shapes

The Montgolfier Brothers

In 1782, while watching a fire in his fireplace, Joseph became interested in the "force" that caused the sparks and smoke to rise. He made a small bag out of silk and lit a fire under the opening at the bottom causing it to rise. The brothers thought the burning created a gas which they called "Montgolfier gas". They didn't realize that their balloons rose because the heated air inside was lighter than the surrounding air.

 Joseph Montgolfier
Etienne Montgolfier
J.M. Montgolfier (left) and J.E. Montgolfier (right)

Joseph was first inspired by the clouds and dreamed of floating amongst them. His first experiment was to fill a paper bag with steam. It was unsuccessful, yielding no more exciting findings than a sodden mass of paper. Joseph's brother, Etienne, attempted to make a paper bag float with hydrogen gas obtained from sulphuric acid and iron filings, but with little immediate success.

In 1782, small-scale success was achieved when a hot air-filled taffeta envelope was seen to rise to the ceiling. The brothers were inspired and they began to think BIG. 

If you put together a really good proposal you may be able to get as much as 3k from the Alumni Foundation by way of a grant and perhaps if they really wanted to support you a loan for the rest. The loan could possibly be repaid through memberships and private hires. I have attached some of the details but it is worth meeting with Rachel Eyre in the Alumni Office in Senate House to see what she thinks. I would be happy to be at the meeting. Iwould suggest that you follow the instructions try and put a great proposal on paper and arrange the meeting. The next grant giving round is however not until November.
Montgolfier balloon
Montgolfier balloon ready to fly
Montgolfier balloon

The first public demonstration of a hot air balloon was made on 4th June 1783. With more taffeta, rope and sky-high hopes, what was really no more than a 38ft paper-lined linen bag took to the sky. The paper was lined with alum for fireproofing and the segments were held together by over 2000 buttons. This contraption rose to a height of 1000m and flew for over a mile.

On September 19th, the Montgolfier brothers conducted a royal demonstration in Versailles. A sheep, a duck, and a rooster become the first hot air balloon passengers. King Louis XVI was not impressed by the stench of the dense smoke, but the brothers believed at the time that it was the smoke that was causing the balloon to rise. Wool, straw and old shoes were used to try and make the densest smoke possible. It was only until later that it was realised that it was the heat that was important, not the smoke.


The first manned balloon flight took place on November 21st 1783, more than a century before the Wright Brothers took to the skies. A concept arrived at from staring at a fire had become a reality within a single year! Jean-François Pilâtre de Rozier (a physicist) and François Laurent, Marquis d'Arlandes were the first human pilots of an untethered flight.

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