We will build a machine that will fly. ~ Joseph-Michel Montgolfier

Joseph-Michel and Jacques-Étienne Montgolfier, also called the Montgolfier brothers (respectively, born Aug. 26, 1740, Annonay, France—died June 26, 1810, Balaruc-les-Bains; born Jan. 6, 1745, Annonay, France—died Aug. 2, 1799, enroute from Lyon to Annonay), French brothers who were pioneer developers of the hot-air balloon and who conducted the first untethered flights. Modifications and improvements of the basic Montgolfier design were incorporated in the construction of larger balloons that, in later years, opened the way to exploration of the upper atmosphere.