Edward Tufte's books on visual information are so brilliant they have nearly eclipsed earlier work. But one publication shouldn't be overshadowed, Jacques Bertin's 1967 Sémiologie graphique.The University of Wisconsin Press published a translation in 1983: Semiology of Graphics: Diagrams, Networks, Maps. It's a splendid translation, with Bertin's masterful illustrations lovingly and faithfully rendered.

Aside from the erudition displayed, Bertin's book is distinguished by the rapport between text and illustration. Here's one of his graphics explaining "vibratory effect," that unpleasant optical phenomenon when certain combinations of black and white appear to our eyes as unstable, with gray or even colored patches that were not intended by the artist. Also known as "moiré," the shimmer is a physiological effect at the retinal level that seems to happen when our brain can't readily determine what is figure and what is ground. Bertin's illustration hopes to show this by displaying a systematic variation of bull's eyes. The vibratory effect should appear when the ratio of black to white area ranges from .4 to .6. In the diagram, that would be with figures located toward the middle. Clearly, the principles of moiré pertain to printed script as well as illustrations. Designers of typeface have long known to avoid letters that create a 50/50 ratio between black and white space.

Anybody have a copy of Semiology of Graphics they want to sell me at a reasonable price? Today on the used book market I can find only one 1983 University of Wisconsin Press copy for sale, and the seller is asking $295 for it. The reprint and softcover editions don't do justice to the orginal illustrations, I hear. Addendum (October 2004): A French correspondant tells me that in 1999 Editions de l'Ecole des Hautes Etudes en Sciences published a fine reprint of Sémiologie graphique with a new preface by Bertin, illustrations as good as the originals. You can find it for sale at 84 euros at <http://www.amazon.fr>.

RH, September 2004