Earlier this year, I read The Song of Names, and commented that a passing familiarity with classical music and Jewish culture would be useful to get the most from the book. I would claim to have significant knowledge of the first of these, and a little (but enough for the purposes of reading that book) of the latter. To get the most from The Difference Engine, I suspect one needs to know not only about Babbage's machines (ironically, Babbage did complete the Difference Engine; it was the Analytical Engine that remained only as sketchy blueprints), but also rather more about the Victorian era than I do.
I found the first couple of chapters (which account for about a hundred pages) dreary and disjointed, quite possibly because I was not picking up on references. When the book really did get going, it wasn't that bad, though I doubt I would really recommend it.
The main characters are well constructed; in particular, my image of Mr Oliphant is disturbingly similar to the portrayal of Mycroft Holmes by Charles Gray in the Jeremy Brett dramatisations of the 1980s, though Dr Mallory, the main character, is a bit more variable, sometimes the hero, sometimes somewhat an anti-hero. I also liked the transposition of the characters of Byron and Disraeli, and I am sure there are many other examples to humour the reader more knowledgeable of the period.
I suppose there are parallels to be drawn between the social collapse of The Stink, and the state of the Napoleon Engine. But as a whole, I could not really see where the novel was going, and though it did conclude, it presented the image of a series of sub-plots without a clear main storyline. From the second-hand bookshop this volume came, and so, I think, it shall return.