YMMV / The Difference Engine

• Aluminum Christmas Trees:
  • During the London riots, Mallory sees a team of steam-engines of Crimean War fame pulling artillery guns. In Real Life, the traction engine had already been in production for farm and circus caravan use by the 1850s, it would have been trivial to adapt them to pull guns and at least one of them operated in Crimea.
  • Scheduled steam carriage services existed for a brief period in the 1820s and 1830s until the Turnpike and Red Flag Acts effectively quashed them in favor of horse-drawn wagons and railroads.
  • The Great Stink took place in real life, just three years later and minus the riots.
  • Edo Japan possessed clockwork dolls known as karakuri (albeit not as sophisticated as the Engine-driven one in the book).
• Genius Bonus: Karl Marx is the leader of a communist Manhattan city-state. Historically, Marx did spend some time living in New York City as a journalist for The New York Daily Tribune from 1852 until 1861, publishing his political ideas and thoughts on important issues of the day.
• Genre Popularizer: For Steampunk, establishing many of its familiar tropes and conventions.
• Inferred Holocaust: The steampunk dream of a Victorian information age is somewhat deconstructed by the heavy hints that they're using it to catalogue people for the purposes of the then-popular doctrine of eugenics. The ending (set in the 1990's) implies that what's left of humanity only exists as simulated information.

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