Geometrische Darstellung der Farbenblindheit
A German medical monograph of 1881 by Bruno Kolbe, published in St. Petersburg by O. Kranz, that uses geometric diagrams to explain colour blindness for physicians and students. The single picture is a numbered engraved figure of an apparatus with a profile head looking through a sight into a box with black side panels, a rotating dark disc and a graduated scale, drawn in fine black-and-white linework. A designer might take its clean technical line drawing style, dark panel framing, and precise labelled letters as a model for scientific diagrams.
