I'm trying to remember the title of a Russian novel which smelled like early Communist propaganda but whose plot was actually very sci-fi for the time period. It was probably written in the late 19th century or early 20th.
Sci-fi elements The most futuristic element in it was the invention and (failed) usage of a massive cannon that could shoot beyond the horizon. The cannon could fire high-tech "cold" explosive decompression shells that would instantly freeze an entire area, silently killing all in its "blast." Otherwise, its tech level is that of late industrial era - people recognize that factories are unhealthy to live near or work in, but factories are still the most important engine of the economy.
An absurdly wealthy man dies with only one very distant relative known. But the executor finds a man who turns out to be his actual child (I think illegitimate.) The previous heir sues and the actual heir agrees to give him half to just get it out of the way. The two men set up opposing cities, one a wealthy, industrial dictatorship and the other an enlightened, natural commune. Both cities flourish initially, although the living conditions of the commune are vastly superior to the industrial city. Hostilities grow between the two cities, almost leading to open conflict before the industrial city (I want to say it was named something super boring, like Steelville) suddenly ceases to operate. A man from the commune infiltrates and investigates (the investigation may have started prior to the industrial city's collapse,) eventually discovering that the industrial city had been preparing to attack the commune. But the doomsday cold bomb cannon had suffered an accident, killing the man in charge. The man had taken the reins so tightly in hand that the industrial city collapsed without him issuing orders, and the communists live happily ever after.
Side Details: The evil heir in charge of the industrial city had two particularly vicious henchmen that the heroic communistic spy had to fight. The industrial city is heavily compared to Germany and the commune is heavily compared to France throughout, with France usually being considered superior (this is why I think it may be pre-WWI.)
Age of the book: I read it less than ten years ago, but it was really, really old. The book felt like it was printed before World War II.