The practical working of the gelatine emulsion process
A technical manual on photography by Sir William de Wiveleslie Abney, published in London by Piper and Carter in 1880, written for practising photographers working with gelatine emulsion plates. Its line diagrams show laboratory and darkroom apparatus: a serpentine washing trough with arrows tracing water flow, a bottle fitted with a glass tube, a bent glass tube with side arms, and a plan of a camera-and-shutter setup. A designer could take the clean, labelled schematic style and the arrow-based flow diagrams as models for instructional graphics.
