THE DOOM OF LONDON (1892) – Written by Robert Barr. In the “far future” of the mid-Twentieth Century the narrator of this tale looks back at the catastrophe that hit London in the 1890s.
The premise is that our narrator is outraged by a piece written by a Professor Mowberry in which the professor ventures the opinion that the destruction of London was an overall beneficial event. His reasoning is that it got rid of millions of unnecessary people. Pretty callous attitude, unless you’re talking about getting rid of the Kardashians.
At any rate we readers are informed that in the mid-Twentieth Century fog has been completely done away with (?), preventing what happened to London in the 1890s from ever happening again. It turns out that what started out seeming to be nothing but the usual London fog was actually deadly gases unleashed from deep in the Earth by careless mining. Continue reading
For Balladeer’s Blog’s review of the first episode of this 1971-1973 series about London by Gaslight detectives from both the Victorian and Edwardian Ages you can simply click 
Episode: THE ABSENT MINDED COTERIE (February 26th, 1973) 
WITHIN AN ACE OF THE END OF THE WORLD (1900) – Written by Robert Barr. No doubt about it, Barr was obsessed with the notion of humanity possibly bringing on its own demise through ill-considered scientific tampering. Recently Balladeer’s Blog reviewed another of his stories, The Doom of London, which mined the same creative territory. 
Balladeer's Blog 