Before that occurred, the Duke of Wellington tried to prevent the acceleration of technological change and social upheaval, leading to a coup d'etat in 1830, and his assassination in 1831. After that event, the Industrial Radical Party proved to have the best prospect of government in the political vacuum that emerged, and the eclipse of the nineteenth century Tory Party and hereditary peerage ensued as a result. Insofar as radical social reform occurred, British trade unions were co-opted to assist the ascendancy of the Industrial Radical Party, much as the Labour Party of Great Britain did in the late nineteenth century in our own world. However, Luddite anti-industrialist working class revolutionaries were ruthlessly suppressed.
Following this success, the Babbage computers become mass-produced and ubiquitous, and their use emulates the innovations which actually occurred during our information technology and Internet revolutions. The novel explores the social consequences of an "information technology" revolution in the nineteenth century, such as the emergence of "clackers" (a reference to hackers), technically proficient people skilled at programming the Engines through the use of punch-cards, such as Théophile Gautier.
In the novel, the British Empire is more powerful than it was in our world, thanks to the development and use of extremely advanced steam driven technology in industry. In addition, similar military technology has enhanced the capabilities of the armed forces (airships, dreadnoughts, and artillery); and the Babbage computers themselves. Britain, rather than the United States opened Japan to Western trade, in part because the United States became fragmented, due to interference from a Britain which foresaw the implications of a truly United States on the world stage. Counterpart successor states to our world's United States include: a (truncated) United States; the Confederate States of America; the Republic of Texas; the Republic of California; a Communist Manhattan Island commune (with Karl Marx as a leading light); British North America (analogous to Canada, albeit slightly larger in this world); Russian America (Alaska); and terra nullius. Additionally, all land in the Americas are colloquially referred to as America (viz. Sybil:Do you know anything about Texas, Hetty? Hetty: A country in America. French own it, don't they?)
Napoleon III's French Empire holds an entente with the British and Napoleon is even married to a British woman. In the world of The Difference Engine, it occupies Mexico. Like Great Britain, it has its own analytical/difference engines, especially used in the context of domestic surveillance within its police force and intelligence agencies.
As for the other world powers, Germany remains fragmented, with no suggestion that Prussia will eventually form the core of a unified nation as it did in our own world in 1871, which may be due to French subterfuge analogous to that pursued in the case of the fragmentation of the United States noted above. As noted above, Japan is awakening after the British ended its isolation, and looks set to become one of this world's leading industrial and economic powers from the twentieth century onward, as they did in our world. Due to Lords Byron and Babbage's intervention, the Irish potato famine never occurred, and there is no mention of agitation for Irish home rule or Irish independence from this British Empire as a result.
Among other historical characters, the novel features "Texian" President Sam Houston, as an exile after a political coup in Texas, a reference to Percy Bysshe Shelley (as a Luddite), John Keats as a kinotropist (an operator of mechanical pixelated screens), and Benjamin Disraeli as a publicist and tabloid writer.
Under the Industrial Radical Party, Britain shows the utmost respect for leading scientific and industrial figures such as Isambard Kingdom Brunel and Charles Darwin. Indeed, they are collectively called "savants" and often raised to the peerage on their merits, causing a break with the past as regards social prestige and class distinction. These new patterns are also reflected in the educational sphere; classical studies have lost importance, and are replaced by more practical concerns (such as engineering and accountancy).
As is the case with special objects in several novels by Gibson, the punch cards are to some extent a MacGuffin.
During the story, many characters come to believe that the punch cards are a gambling "modus," a program that would, theoretically, always allow the user to place reliable bets. This is in line with Ada Lovelace's penchant for gambling (in both the novel and actuality). Only in the last chapter is it revealed that the punched cards represent a program which prove two theorems which in reality would not be discovered until 1931 by Kurt Gödel. Ada Lovelace delivers a lecture on the subject in France.
Defending the cards, Mallory gathers his brothers and a policeman to fight the revolutionary Captain Swing who leads a London riot during "the Stink", a major episode of pollution in which London swelters under an inversion layer (comparable to the London Smog of December 1952).
After the abortive uprising, Oliphant and the pseudonymous former Sybil Gerard meet at a cafe in Chablis. Oliphant informs her that he is aware of her true identity, but will not pursue it, although he does want information that would compromise her seducer, Charles Egremont MP, now regarded as an obstacle to the strategies and political ambitions of Lords Brunel and Babbage. Sybil has longed for the opportunity for vengeance against Egremont, and the resultant political scandal destroys his parliamentary career and aspirations for a merit lordship. Oliphant also encounters a Manhattan-based group of feminist pantomime artists, uncannily similar to contemporary feminist performance artists involved in debates over US National Endowment for the Arts funding in the late eighties and early nineties in our world.
After several vignettes that elaborate on the alternate historical origins of the world of The Difference Engine, Ada Lovelace delivers the aforementioned lecture on Godels Theorem, as its counterpart is known in our world. She is chaperoned by Fraser, and castigated by Sybil Gerard, who is still unable to forgive Ada's own father, the late Lord Byron, for his role in her own father's death.
At the very end of the novel, there is a dystopian depiction of an alternate 1991 from the vantage point of Ada Lovelace. Throughout the novel's latter sections, there are references to an "Eye", which appears to be a metaphor for Jeremy Bentham's Panopticon- the concept of omnipresent surveillance technology initially mooted for nineteenth century prison architecture, and the subject of contemporary concern about its intrusions against human rights and civil liberties from authoritarian western societies who use the development of information technology to monitor, regulate and police their populations, as Michel Foucault noted in his Discipline and Punish (1977). Human beings appear to have become digitised ephemeral ciphers at the mercy of a sentient artificial intelligence, implied to be as a consequence of this world's accelerated development of information technology.