The Difference Engine is an alternate history novel that centers on the premise “what if the computer age had arrived a century earlier?” Here, massive technological and cultural changes were brought about by the completion and perfection of Charles Babbage’s Analytical Engine. As a result of the perfected analytical engine the Industrial Revolution doesn’t happen in trickles but rather a rapid, radical sweep.
Great Britain becomes a true titan, running unopposed. It’s military might bolstered a hundred fold with technological marvels like the steam-powered dreadnaughts, calculating cannons, machine guns, all kept running smoothly by information technology managed by steam-driven supercomputers. Britain now stands to improve the world, by force or otherwise…
The old structure of aristocratic rule has been done away as unnecessary trappings of the old world system. In its place a new social elite rises up composed of the technocrats and the cognoscenti of the complex language of engines. Those who cannot wield technology or refuse to make use of the wondrous new technology form the bottom rung of the social ladder.
Much of the novel’s action though revolves around a handful of colorful characters taken from the pages of fiction as well as real life such as: the daughter of slain Luddite leader and politically inclined courtesan, Sybil Gerard, the titular Sybil from Benjamin Disraeli’s novel and Laurence Oliphant, the larger-than-life British multi-hyphenate, doing espionage work for the queen in the novel. The gentleman-adventurer Edward Mallory, nicknamed “Leviathan” for his paleontological discoveries, also joins them rounding out their troupe. The group is bound together by a common mission: they after a collection of mysterious computer punch cards; they don’t necessarily know that the punch cards do, but they do know that together these data cards have the capacity to change the world, as they know it.
The cards are thought to be components of a complex program that would enable the wielder to make complex calculations on matters involving statistics and probability, such as gambling or say, the stock market. The difference though is that it does it with a vast degree of accuracy technically allowing the user of the program to place consistently winning bets or make the most profitable trades or purchases of stocks. It is revealed much later on in the novel that the cards are actually based on two theorems posited by Kurt Gödel, that wouldn’t be learned until 1931.
One of the factions trying to gain possession of the cards is the revolutionary leader, Captain Swing. He has organized a large riot and has struck during a meteorological phenomenon simply called “the Stink”---a parallel of the London Smog of 1952. The uprising is successfully suppressed through the efforts of Mallory and his team. Once the bedlam dies down Sybil and Laurence Oliphant meet in Paris to discuss certain details of their collective mission. He reveals that he has discovered Sybil’s true identity, and although he is not bothered by her deep political ties he does want to secure from her as much damning information concerning Charles Egremont MP, Sybil’s lover/target, as he can get his hands on. Egremont is considered a threat to the aspirations of Lord Brunel and Babbage, whom Oliphant serves. Sybil has been searching for a chance to destroy Egremont for his involvement in the death or her father and cooperates with Oliphant. Together they manage to orchestrate a political scandal that destroys his career as well whatever chance he had a gaining lordship.
The rest of the novel unfolds with details concerning the alternate historical events that are analogous to real-world historical events, explaining the development of a steampunk world. Events come to a head as Ada Lovelace, conveys her discovery---a theorem analogous to Gödel's incompleteness theorems---nearly a century earlier than in our reality, setting into motion a series of events that trigger even more fantastic developments in technology.
The novel ends with a description of the world of The Difference Engine, now in the “future” year 1991. The narrative is revealed later on as being told from the vantage point of a computer on the verge of attaining self-awareness.
