I read Agatha Christie's Evil Under The Sun recently*. The story is set in Leathercombe Bay, a fictionalised version of Burgh Island in Devon, famous for its elaborate art deco hotel and the fact that it is only accessible at low tide. The hotel in Christie's novel is noticeably more traditional in appearance and her Leathercombe Island is a reduced and simplified version of the real thing. I know this because the book begins with a handy map of the Island with the novel's significant locations marked on it.
I've always been a sucker for maps at the start of books, probably due to a nostalgia for the fantasy worlds invented in the books I read as a child. In Evil Under The Sun the map plays a structural role though. It helps to pin down the action and in a very mechanical way delimits the movements of the various protagonists. The map includes a north sign and, helpfully, the island contains four bays more or less located at each point of the compass. This fictional geography forms the basis for a stilted and theatrical plot where people's actions and the movements of the sun are intertwined (The murder, for example, takes place at Pixie Cove, a place deserted in the mornings because it faces West**). Theatrical is the key word here because, as in most of her books, Christie reduces the action to a small and confined stage set from which none of the characters can escape.
I've only read one other Agatha Christie novel and that was The Murder At The Vicarage, a book I bought largely on the strength of its sub-Magritte cover art. It too contains a map, along with two plans. These drawings form a kind of architectural set, moving from the scale of a location plan showing the village in which the story is set through a site plan of the vicarage and its immediate surroundings and, finally, a detail plan of the library in which the murder takes place. Again, the plans are intrinsic to the plot and to the deduction of the murder. The various movements of the characters and the possibility of them being witnessed depends on entrances and exits to rooms and houses. The drawings provide the factual basis against which various dubious alibis and false claims are exposed.
Like the fantasy landscapes of children's books, these drawings describe a place that is entirely consistent within its own logic. As it doesn't actually exist it can't contain any errors and whatever is drawn becomes unchallengeable fact. This is interesting because drawings play a slightly different role in architecture. For architects drawings are a source of ambiguity. Or rather, their capacity for ambiguity is a source of concern. We rely on them for accuracy in the form of surveys and dimensioned plans and we can even get sued if they are incorrect, but we also manipulate them for our own ends. Architects frequently draw things in subtly inaccurate ways in order to 'fudge' a key view or exploit the full range of compositional devices - line weight, notation, colour and shading - in order to seduce the viewer.
Even the modes of projection are unreliable. No one ever actually sees an elevation, for instance, because orthographic projection takes no account of the way that objects recede in perspective or the specific point of view of the observer. The global view afforded by orthographic projection leads architects to focus on issues of proportion and composition that make more sense on the page than in reality. A beautiful or elegant plan is only really experienced through its representation in drawing.
Robin Evans has investigated this issue in depth, looking at how various methods of drawing projection - orthographic, isometric, perspectival - have influenced and shaped the development of architecture. Evans calls this the projective imagination or, less romantically, the projective cast. Projection in this sense is both metaphorical and literal, describing the ways that we imaginatively project a space that doesn't yet exist and the way that this space is marked out on the paper, literally constrained by the lines of projection.
The truth of drawings is thus always partial and contingent on technique. The difference between an architect's plan and Christie's one is slight but significant. Her plans don't show wall thicknesses or detail but they do include things that an architect might leave out, such as objects in rooms or the movements of a person. Architects' plans rarely describe either. They are more concerned with proportion, harmony (or sometimes its opposite), construction and materials. For Christie, the drawings record actions and events. Even when these aren't explicitly drawn, they are implied by the narrative surrounding them. Because these actions are often improbable, stretching credibility to breaking point, the drawings form a kind of proof, evidence of what is and isn't possible within the logic of the plan.
Perhaps, for a novelist, drawings are more reliable than words. As a less familiar form of representation they might be regarded as less capable of manipulation. For architects, drawings frequently prove unreliable and buildings strain at the limits of what they can accurately describe. It might be interesting then to speculate on what the history of architecture might have looked like had words been the primary means by which architects described buildings. In the the construction sequence of a building, drawings tend to come first and words after. Architects describe buildings through drawings which critics then re-describe with words. Conceivably this sequence could be reversed.
* There is a good description of the book's social milieu in Travis Elborough's history of the English seaside, Wish You Were Here.
** The book could, in a generous light, be read as a satire of the cult of the seaside and sun-worship in the 1930's.