Jacques Etienne de Montgolfier & Joseph Michel de Montgolfier

1745-1799

French Aeronautic Inventor

1740-1810

French Aeronautic Inventor

The Montgolfier brothers were eighteenth-century French businessmen who enjoyed conducting scientific experiments in their spare time. Becoming interested in the age-old dream of flying, they discovered an important aeronautical principle involving balloons and in 1783 were responsible for the first human flight in history. Since they worked closely together on this project and since neither accomplished anything else particularly noteworthy, their biographies are always combined.

Joseph and Étienne were the twelfth and fifteenth children of Pierre Montgolfier (1700-1793), a wealthy paper manufacturer whose factories were located near Lyon in southern France. Joseph was largely self-educated. He tried the paper manufacturing business but had little success. He was shy and extraordinarily absent-minded, two qualities that hampered his career. He was, however, very interested in technological advances. After the French Revolution (1787-1799) he retired from business and moved to Paris, where he worked at the Conservatoire des Arts et Métiers and helped establish the Société d'Encouragement pour l'Industrie Nationale in 1801.

Étienne was sent to Paris to study mathematics and became an architect. In 1772 his father decided that his older brothers were not capable of running the family business; Etienne was asked to give up architecture and become a paper manufacturer. He was a very successful businessman, especially after he and Joseph became famous. In 1784 King Louis XVI designated the firm as a manufacture royale. Paper manufacturing was Étienne's main pursuit for the rest of his life.

Joseph was the first to tinker with the problem of human flight. By 1782 he had stimulated Étienne's interest as well and the two men began conducting experiments in their leisure time. They initially tried to use hydrogen, discovered in 1766, to raise balloons, since it was 14 times lighter than air. But hydrogen was very combustible, expensive to make, and seeped through cloth as if it were a sieve. The brothers' experiments with silk and paper models led them to conclude that hydrogen could not be used to achieve flight.

Joseph then discovered that heated air had lifting power. Étienne used his mathematical background to work out the size and shape of a balloon to hold this heated air. They sealed the cloth with strips of paper, a natural idea given their family business. They erroneously believed that it was smoke that caused the balloon to rise. After numerous experiments, they settled on a mixture of damp straw and wool as the fuel providing smoke with the greatest lifting power. In one of history's fortunate accidents, these two scientific amateurs had inadvertently solved the problem of flight, because heated air becomes sufficiently rarefied (less dense) to lift a balloon.

On June 4, 1783, the Montgolfier brothers publicly demonstrated their discovery when they launched a 35 ft (10.67 m) balloon from a small town near Lyon. It ascended about 6,000 ft (1,829) and floated over a mile (1.61 km) away. Although it was unmanned, this was a giant step toward human flight. Joseph went to Lyon and Étienne to Paris to publicize their success. Étienne's mission was more significant because he succeeded in gaining the attention of Louis XVI, who loved dabbling with mechanical devices. In September, Étienne launched another montgolfière (the name given to hot-air balloons) for the royal court at Versailles. It carried several animals, all of which survived the ascent. Human flight was the next logical step.

Étienne, however, had competition. A popular Parisian science lecturer, Jacques Charles (1746-1823), had succeeded in constructing a hydrogen balloon, which he had flown unmanned. He and Étienne were now in a race to see who would get the first human aloft. Étienne constructed his balloon faster and won the race. On November 21, 1783, a montgolfière carrying two men floated over Paris for about 20 minutes. The two passengers were Jean François Pilâtre de Rozier (1757-1785) and François Laurent, marquis d'Arlandes (1742-1809). They were the first men in history to fly. Ironically, two years later de Rozier was the first human killed in an aerial accident.

Although the family received government grants and was ennobled in December 1783 (hence the "de" in their name), the brothers soon lost interest in aeronautics. Joseph made only one ascent, Étienne none at all (both men were middle-aged). Étienne returned to his paper manufacturing, while Joseph turned his attention to other inventions, the most important of which was a hydraulic device for raising the level of water. They had proven, however, that human flight was possible. Their success stimulated the development of the hydrogen balloon, which was far superior to their montgolfières in terms of range (both distance and height) and which soon supplanted their hot-air balloons.

ROBERT HENDRICK