A Luxembourgian publisher, inventor, and writer, he is particularly known for Ralph 124C 41+ (1911) and other works of science fiction. In 1908, he founded Modern Electrics magazine.
He worked as an electronics engineer and an inventor before delving into science fiction.
His name was given to the Hugos (the annual World Science Fiction Convention awards).
He was married three times. Rose Harvey was his first wife; Dorothy Kantrowitz was his second, and Mary Hancher was his third.
He and H.G. Wells were both important science fiction authors.