Cincinnatus’ world is a rather old-fashioned place, civilised according to an early 20th-century Mitteleuropean style. Nevertheless the novel refers at several places to a more technologically-advanced deep past. The town keeps a ‘venerable, decrepit aeroplane, with motley patches on its rusted wings.’
There was in town a certain man, a pharmacist, whose great grandfather, it was said, had left a memoir describing how merchants used to go to China by air. No longer, though. In this novel ‘time gently dozes.’ Cincinnatus reads an antique magazine and is amazed at the plush life his ancestors lived:
That was a remote world where the simplest objects sparkled with youth and an in-born insolence, proceeding from the reverence that surrounded the labour devoted to their manufacture. Those were years of universal fluidity; well-oiled metals performed silent soundless acrobatics; the harmonious lines of men’s suits were dictated by the unheard-of limberness of muscular bodies; the flowing glass of enormous windows curved around corners of buildings; a girl in a bathing suit flew like a swallow so high over a pool that it seemed no larger that a saucer; a high-jumper lay supine in the air, having already made such an extreme effort that, if it were not for the flaglike folds of his shorts, he would seem to be in lazy repose; and water ran, glided endlessly; the gracefulness of falling water, the dazzling details of bathrooms; the satiny ripples of the ocean with a two-winged shadow falling on it. This is a familiar trope from SF of course: the present seen from the perspective of a notional future and so reimagined. But I don’t know of any SF writer who treats it quite like Nabokov does here. This is not just because the language so gorgeously recreates the images under description—(that high-jumper!)—although it does; but rather because where most SF writers are interested only in the minutiae of the content of their imagined worlds, Nabokov’s description engages the medium, time, directly, by balancing atemporal form against formless endless fluidity. On the one hand the timelessly frozen (the diver, the athlete) in mid-action; on the other, the water. It's a Nabokovian Dying Earth or Book Of The New Sun, and as intensely poetically SF in its precise imagism as all Nabokov.