JF Ptak Science Books Post 1867
Montague B. Black (b. 1884), an artist and illustrator, pulled the curtain back from the future back there in 1926 to what he thoiught might be the following scene of London in 2026:
The airship (of an undetermined power source) has an ad on the side of it reading "Overland Line, London-Sydney"--and by "overland" the artist is not thinking of the old-time "overland" as in prairie schooners and such, but quite literally "over the land". We can also see an ad on the side of a building for an "Underground to Scotland, Glasgow 2hrs 45 mins". There are also named buildings such as the London Bridge Air Depot and the Airtaxi Ltd. The skyscrapers really aren't all that enormous--I see one or two perhaps in the background that might be a hundred stories or so, but the buildings in the foreground are definitely of modest expectation.
There are however dozens of flying machines in the sky, though with the exception of the three large airships, a hundred years has not paid too many benefits to the other aircraft.
Black did create an interesting poster for the White Star line, featuring a certain famous luxury liner--of course the man was just like anyone else, and could not see into the future for the Titanic, nor could he imagine slightly accelerated designs for aircraft. He did manage to portray a transportation system that would be heavily dependent on air travel. That said, he left plenty of room for speculation on the future of the Underground, as we can see in all of this future-glory that no matter the amount of accomplishments in the sky, trains would still be running underground. Black got those two things right, at least.