In Lampedusa’s delightful novel of the Sicilian Risorgimento the author describes some piece of behavior by analogy with arrival in a jet airplane: an attention-grabbing anomaly, given that the novel is set well before the jet age and is narrated, not by the Prince but certainly in a way that is oriented towards his point of view; the principle violated here seems to be “do not use concepts in narration unavailable to the focalising character” (Genette’s not very helpful term).
One way to restore harmony with the principle would be to assume that, in the story, flight by jet aircraft is available in the 1860s. But this is wholly unattractive: nothing else in the story is remotely consonant with such a suggestion, though of course such violations of history are available to an author fiction.
The reference indicates, surely, that the narrator, and not merely the author, is a mid-twentieth century person looking back one hundred years and that his (surely it is a he) focus on the Prince is a matter of moment-by-moment decision rather than consistent commitment. If the reference to jet aircraft sounds awkward (it does to me) that may be because the analogy itself is a somewhat contrived and because placing the narrator so specifically in time clashes with his omniscience.
All this is yet another illustration of the fact that truth matters to literary evaluation; these questions simply would not arise if, as a matter of fact, jet travel had been available in 1860. But in an earlier version of this I mentioned another, more evident clash with truth, claiming that, after the Ball, the Prince sees Venus in the west at morning. Such a thing would not happen in this world, given the relative positions of the Earth, Venus and the sun. And it would be odd for the Prince to see such a thing and not be immediately struck by its impossibility—he was a keen amateur astronomer (as was, in fact, his real-life model, Lampedusa’s great grandfather).
Filippo Contesi quickly pointed out that the text actually says “east”, not “west”. I’ve not been able to find any text in Italian or English that says “west”. Did I invent this? There are places on the internet which have the passage saying “west”, so the error has a longer history. Could there be a printed text somewhere with “west” in it? The wonderful Giulia Ichino at Mondadori was kind enough to check for me and found none. So if anyone out there believes that Lampedusa made a mistake here we can assume they are wrong.