Henry de Graffigny, pen name of Raoul Henri Clément Auguste Antoine Marquis (1863-1934), was a French polygraph and popular-science writer born in Graffigny-Chemin (Haute-Marne). An early aeronaut who made numerous balloon ascents in the late nineteenth century, he devoted his career to a prolific popularizing output, more than two hundred titles spanning aeronautics, electricity, mechanics, astronomy, and chemistry. He also wrote speculative fiction, including the Aventures extraordinaires d'un savant russe (1888-1896), which makes him one of the founders of French science fiction. Louis-Ferdinand Céline drew on him as the model for Courtial des Pereires in Death on the Installment Plan. Irons-nous dans la Lune? (1932) is among his last works and his most explicit contribution to French astronautical literature.