“Scientific romance” is now commonly used to refer to science fiction of the late nineteenth and early twentieth centuries, as in the anthologies Under the Moons of Mars: A History and Anthology of “The Scientific Romance” in the Munsey Magazines, 1912-1920 and Scientific Romance in Britain: 1890-1950. One of the earliest writers to be described in this way was the French astronomer and writer Camille Flammarion, whose Recits de l’infini and La fin du monde have both been described as scientific romances. The term is most widely applied to Jules Verne, and H. G. Wells, whose historical society continues to refer to his work as ‘scientific romances’ today.from https://en.wikipedia.org/wiki/Scientific_romance
Edgar Rice Burroughs’s A Princess of Mars (1912) is also sometimes seen as a major work of scientific romance, and Sam Moskowitz referred to him in 1958 as “the acknowledged master of the scientific romance,” though the scholar E. F. Bleiler views Burroughs as a writer involved in the “new development” of pulp science fiction that arose in the early 20th century. The same year as A Princess of Mars, Sir Arthur Conan Doyle published The Lost World,which is also commonly referred to as a scientific romance.
1902 saw the cinematic release of Georges Méliès’s film Le Voyage dans la Lune (A Trip to the Moon); the time period and the fact that it is based partially on works by Verne and Wells has led to its being labelled as a scientific romance as well.
The latest Coode St Podcast, episode 451, has an interesting discussion on the “scientific romance” with John Clute: John Clute and Science Fiction Repeting the Future