The Collaborative International Dictionary of English v.0.48:

Montgolfier \Mont`gol"fier\, n.
   A balloon which ascends by the buoyancy of air heated by a
   fire; a fire balloon; -- so called from two brothers, Stephen
   and Joseph Montgolfier, of France, who first constructed and
   sent up a fire balloon.
   [1913 Webster]

WordNet (r) 3.0 (2006):

Montgolfier
    n 1: French inventor who (with his brother Josef Michel
         Montgolfier) pioneered hot-air ballooning (1745-1799) [syn:
         Montgolfier, Jacques Etienne Montgolfier]
    2: French inventor who (with his brother Jacques Etienne
       Montgolfier) pioneered hot-air ballooning (1740-1810) [syn:
       Montgolfier, Josef Michel Montgolfier]