Joseph Théophile Maurice Moselli (1882-1941), was an incredibly prolific writer of adventure fiction of all sorts for the French pulps. He wrote mostly as José Moselli, but according to Wikipédia also wrote as Jacques Mahan, Pierre Agay, J. Fauconnier, Nord-55-Est, and Ledam as well as, less frequently, Jack Duridan, Jules Dupont, Pierre de Villebrune, Jim Houch, Jacques North and (according to Georges Fronval) Captain Harry et Explorateur.
Moselli could have become another H.G. Wells had the publishing opportunities existed. He embodied many of the qualities of modern science fiction writers: a seemingly endless variety of daring ideas, introduced seriously and not for satirical purposes, exploited logically and not serving merely as a pretext for a wild adventure; featuring fully developed, believable characters rather than cardboard hero figures (Lofficiers 363).
Moselli’s science fiction appeared exclusively in popular magazines like L’Épatant, L’Intrépide, Cri-Cri, Le Petit Illustré and others, as well as in collections of penny dreadfuls such as “Collection d’Aventures”. It was not until 1970 that any of his magazine publications were republished in books form: first La fin d’Illa, and then Le messager de la planète and La cité du gouffre. Of all these, only La fin d’Illa has been translated into English: Brian Stableford’s Illa’s End was published in 2011. This story was originally published between January and July 1925, in Sciences et Voyages: it was, says Versins, “a marvel which remained buried in this magazine and in the memory of fans for thirty-seven years” before being reprinted in the magazine Fiction in 1962. It was a story of the great civilisation that existed on a Pacific continent in distant prehistory, that was destroyed in a nuclear war.
Le messager de la planète (1924) is about an alien from Mercury who crash-lands in Antarctica and is discovered by explorers (in the end he is killed and eaten by their dog-team); Le voyage éternel ou les prospecteurs de l’infini (1924) tells the story of a lunar expedition that fails to return home; Le maître de la foudre (1922) is about a Japanese inventor with a ray that can destroy ships from a distance; L’île des hommes bleus (1938-39) is about an island that floats high above the Earth, the “blue men” surgically altered to live with the minimum of atmosphere.
Moselli was born in Paris, and became at quite an early age a cabin boy aboard a sailing ship. His life was harsh, but he travelled widely, and endured it for some years. Eventually he jumped ship, somewhere on the west coast of South America, where he stayed for a while. He eventually returned to France where, in Marseilles, he appeared (voluntarily) before a board of the (French) Merchant Navy, and was pardoned for his desertion, and recommended for officer training.
As an officer, one of his first tasks was to oversea the transport of a giant crane from Marseilles, through the Suez Canal, and across the Indian Ocean to Saigon. At some point (there are no clear dates in any of this) he returned to France, and decided to write. His first piece appeared in November 1910 in L’Intrépide.
After his war service, he returned to writing, which he kept up without cease until 1939, when he retired to the south of France; he died at Le Cannet (Alpes-Maritimes), in 1941.
I have taken my information about Moselli’s life from two articles by Georges Fronval, reprinted on the website www/roman-daventures.com. There is a certain amount about his fiction in Versins, Encyclopédie de l’utopie … and in Jean-Marc Lofficier and Randy Lofficier, French Science Fiction, Fantasy, Horror and Pulp Fiction (Jefferson NC: McFarland, 2000); and a limited amount about his life on Wikipédia.