The French inventors and industrialists Joseph Michel (1740-1810) and Jacques Étienne (1745-1799) Montgolfier were brothers who invented the hot-air balloon, an important step in the development of aeronautics.

Both Montgolfier brothers were born at Annonay, Joseph in 1740, Étienne on Jan. 7, 1745. Their father owned a large paper mill and gave them a good education. Joseph was placed in a private school, but he left to start a chemical business by himself. Paris, with its famous scientists, attracted him, but after a short stay he was called back to Annonay to help his father run the paper mill. He promptly tried to introduce new techniques into the business, which resulted in his father's giving him funds to establish a business of his own. However, Joseph's inexperience soon led to considerable financial losses.

Étienne's youth was a more conservative one. He received training as an architect, which included...