Mapping a Face

It’s been over a year since I last posted, but with work on the PhD now complete (call me Dr!) I’ve felt an urge to revisit some ‘fascinators’ that hadn’t made it into the thesis. Tidying old files, I rediscovered a “precise contour map” of a face, which reminded me of the face-mountain (Gesichtsberg) I wrote about at the outset of the PhD (that also hasn’t made the final cut). So here they are compared and contrasted.

To give a bit of backstory, much was written by mapmakers on “full-face” representations of place. OS master draftsman, Robert Dawson, thought maps should “be considered a full-face portrait of a county” and a “pictural exhibition to the eye”. V. R. von Streffleur, like Dawson, thought systematic (mechanical) drawing methods – such as contour lines – would not exhibit the character of a face. To illustrate this, he drew two versions of a “face mountain”. Figure 1. Shows contours, interspersed with vertical hachures that – whilst “mathematically correct” – he thought “no one could call this example physically correct”. He is right, when we look at a face, we search out the eyes to tell us something of the character. Yet as the contours on his example are drawn at roughly 5cm intervals, the eyes are missing.

Of figure 2, on the right, he says: “instead of the ideal horizontal lines, one draws the real lines of form existing in nature”. But how can we know if these lines are as ‘precise’ as contours appear to be? How has the upper lip-to-nose distance been measured? Does it matter? And perhaps exaggerating the length of a nose actually better conveys some aspect of a character? 

We get more information – less blank space – if the contours are reduced from a 5cm to a 1mm interval. A. H. Robinson’s face-mountain (or ‘precise contour map’ of a face, as he termed it) has contours so tightly packed that the shape of the eyes begins to emerge. Streffleur’s figure 2 exhibited eyebrows, and a hint of eyelash; small features that help convey character. All hairy protuberances are missing from Robinson’s face. His has a clean, serene quality, or perhaps the expression is just vacant. Which shouldn’t surprise as the original plaster model face drawn from was also devoid of lashes, freckles, and with eyes closed, the face is devoid of expression. 

Robinson approaches the problem of expression with these words: “the most effective visual techniques did not give precise terrain information. Likewise, methods that gave precise terrain values were the least effective visually.” He suggested there is an “incompatibility between striving for visual realism on the one hand and precise attribute values on the other”. Elsewhere his writing was more complementary of contour lines – for their ‘precise values’ – so it was a surprise to read on, and find that, just as one might exaggerate the length of a nose on a drawing, one could equally shift a contour line on a map. A problem with ‘precision’, he suggests, is that “the arbitrary location of contour slices through the terrain … [can] cause omission or distortion of small features … Sometimes it is desirable to shift contours, within the limits of absolute accuracy, to more effectively portray a feature that is prominent in the landscape but not adequately revealed by the accident of geometry.” One wonders then, how often the OS might have shifted the position of a contour line. Perhaps it still goes on?

Now the PhD is done, I hope to have time to post more such ‘out-takes’. The body of the thesis however is to remain ‘on ice’ while I figure out how it might become a book.

• The images are taken from Arthur Howard Robinson, Elements of Cartography, 6^th ed. (Chichester: John Wiley & Sons, 1995), 541 fig. 27.19 captioned: “The vertically lighted plaster model and a precise contour map with a 1mm. interval derived from it. The contours were obtained by photogrammetric methods. (Courtesy G. Fremlin).”
• And
• V. R. v. Streffleur, “Der gegenwärtige Standpunkt der Bergzeichnung in Plänen und Landkarten,” [The current situation of Mountain-drawing on plans and maps] in Östereichische Militärische Zeitschrift, IX (Wien, 1868), Tafel no. 3, descriptions from page 233.

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