My go-to source for the history of scientific romances is Brian Stableford’s 1985 book Scientific Romance in Britain 1890-1950. (While long out of print, this book is worth its weight in gold.) In Stableford’s account, scientific romances are very much the products of the environment they evolved from. Before the 1890s, publishing in Britain was divided into two rigid categories. On the “respectable” side were the great triple-decker novels, conservative in both style and content, and physically inaccessible to anyone who wasn’t wealthy or who didn’t have access to a circulating library. On the less reputable side were, of course, the penny dreadfuls; cheap to make, quick to read, easy to forget, and not that well-written. Scientific romances (and to a certain extent modern sf) tend to work best in the range between short stories, novellas, and single novels; long enough to properly extrapolate from a central idea, but not so long as to wear out their welcome. It was only at the end of the 19th century, with the decline of the triple-decker, the rise of a literate middle class, publications that catered to them, and of writers that could comfortably support themselves writing for this new audience, that scientific romances had the space and opportunity to emerge. Naturally, this was a different class of writers with different influences that those who had written the gothic works from earlier in the century, so scientific romances evolved in both style and content in a much different direction. (As an example, scientists in 19th-century Britain had a unique tradition of penning essays to explain their theories and their significance to a more general audience, a tendency that was absorbed wholeheartedly into the scientific romance, to the point that both scientists and novelists tried their hands at both essays and stories every so often.)
I was thinking about the literature of 1897 and it got me thinking about the Scientific Romances and how they differ from the Gothic Romances or Gothic Horrors of the age. Clearly, there is some overlap and Frankenstein (much earlier but still relevant) crosses those borders many time without showing a passport for either but by the late 19th you couldn't really compare say 'The War of the Worlds' to 'Dracula'. Where did they diverge so wildly? Or did they?
That’s a really good point, and I’m sorry I took so long to get to this question! Arguably, Frankenstein himself brings this up- he started out reading ancient mystic texts and moved to more scientific ones later- but I guess there started to be a clearer divide between what we’d call fantasy and what we’d call science fiction as science itself became better known. You could probably write gothic science fiction in the mode of Asimov, where the science is there to set up philosophical and psychological issues- I’d certainly read about the drama between robot heirs to their creators’ estate and legacy- but the divide certainly feels there. Returning to H. G. Welles, maybe The Invisible Man is the midpoint? Or maybe it’s when “scientist” became a common enough profession to not seem mysterious? Any followers with ideas on this subject, help me out here!