In recognition of their achievement, Étienne received the ribbon of St. Michael, Joseph was awarded a pension of 1,000 livres and King Louis XVI elevated their father Pierre to the French nobility (thereafter bearing the surname “de Montgolfier”) Among many additional honors bestowed on Joseph Montgolfier were membership in the Legion of Honor and appointment to the Institute of France. Thereafter, the brothers published books on aeronautics and continued their scientific careers: Joseph invented a calorimeter and the hydraulic ram, and Étienne developed a process for manufacturing vellum. Jacques-Étienne Montgolfier died on 2 August 1799, at age 54, in Neuchâtel, Switzerland; Joseph-Michel Montgolfier died at Balaruc-les-Bains, France, age 69, on 26 June 1810.
However, Joseph-Michel supported the French Revolution, and was appointed Administrator of the National Conservatory of Arts and Crafts. The French astronomer Jérôme Lalande, a close friend, told Sylvain Maréchal, author of the Dictionary of Ancient and Modern Atheists, that Montgolfier was an Atheist—or, as Joseph Mazzini Wheeler put it in his Biographical Dictionary of Freethinkers of All Ages and Nations (1889), “A friend of Delambre and La Lande, he was on the testimony of this last an atheist.” Indeed, that venerable vetter of the virtuous, the Catholic Encyclopedia, conveniently mentions only Joseph-Michel’s pious brother!
"Paradise is one of the crass fictions invented by high-priests and fathers of the Church, a fiction whose purpose is to requite the hellish torments of people on earth with the soap-bubble of a hope of peace in another place."