The Forever Engine, due for publication in early January, is a prequel novel to the Space 1889 setting by the man who started it all: Frank Chadwick.
Although there have been a number of eBooks set in the Space 1889 universe, I believe this is the first honest-to-goodness print novel to hit the shelves.
From the book's Amazon page:
London 1888. His Majesty’s airships troll the sky powered by antigrav liftwood as a cabal of Iron Lords tightens its hold on a Britain choked by the fumes of industry. Mars has been colonized, and clockwork assassins stalk the European corridors of power. And somewhere far to the east, the Old Man of the Mountains plots the end of the world with his Forever Engine.The 352-page paperback, published by Baen Books, is available to pre-order from the UK Amazon site as well.
Enter Jack Fargo. Scholar. Former special forces operator in Afghanistan. A man from our own near future thrust back in time — or to wherever it is that this Brave Victorian World actually exists. Aided only by an elderly Scottish physicist, a young British officer of questionable courage, and a beautiful but mysterious spy for the French Commune, Fargo is a man on a mission: save the future from irrevocable destruction when the Forever Engine is brought to full power and blows this universe, and our own, to smithereens.