This dislocation applies most obviously to Timeslip fantasies. Deliberate anachronism may help establish timelessness, as with Merlin in T H White's The Sword in the Stone (1938), who lives backwards through time and whose wizardly paraphernalia thus includes cigarette cards and the Encyclopedia Britannica. Milieux are more subtly mixed for timeless effect in M John Harrison's Viriconium series.
Anachronism is an obvious source of Humour: Duke Astolph, drawn from Ariosto, boasts of his Winchester school scarf and membership of London's "Sphinx Club" in The Castle of Iron (1941) by L Sprague de Camp and Fletcher Pratt; Bored of the Rings (1969), Henry N Beard's and Douglas C Kennedy's Harvard Lampoon Parody of J R R Tolkien, relies heavily on thrusting anachronisms into a travestied middle-earth, US brand names being regarded as particularly hilarious (one character is the Jolly Green Giant); Robert Asprin's Myth Conceptions (1980) painfully describes a fantasy Inn which is all too evidently a modern fast-food outlet; Terry Pratchett has systematized anachronism through a joke theory of "morphic resonance" between Earth and his Discworld, with druids rebooting their 66-megalith stone-circle computers, armoured guardsmen echoing tough lines from tv police procedurals, playwrights recreating William Shakespeare's Macbeth (1623) in the manner of Samuel Beckett's Waiting for Godot (1955), etc.; and Esther M Friesner's Gnome series likewise uses much anachronistic humour.
Inadvertent anachronism may or may not harm a book. J R R Tolkien's The Lord of the Rings (1954-1955) has potatoes in what is stated to be prehistoric Europe. Ursula K Le Guin's acute ear for Diction led her to skewer Katherine Kurtz's Celtic Fantasy Deryni Rising (1970) in "From Elfland to Poughkeepsie" (1973) for its too-modern, too-US dialogue; similarly, in the medieval setting of Peter Morwood's The Dragon Lord (1986), words like "scenario" and "paranoia" can jar. Even the glaring Prehistoric-Fantasy anachronism of humans coexisting with Dinosaurs has gained a kind of common-law acceptance through sheer familiarity. Some anachronisms are debatable: was Guy Gavriel Kay unwise to make the aviational term "Aileron" a major character's name in The Fionavar Tapestry? Some are publisher-enforced: Garry Kilworth's The Drowners (1991) uses metres and litres in 19th-century England, its young audience being deemed incapable of understanding yards and gallons.
In general, anachronism involves perceived intrusions from the future; similar contact with the past is less troubling, unless the gap of years compels the jolting recognition of a Time Abyss. An exception is the curious Ghost Story Time Out of Mind (1986) by John R Maxim (1937- ), in which it is through flashes of 19th-century scenes and events that the present-day characters first realize the Wrongness of the situation. [DRL]