Photography with emulsions: a treatise on the theory and practical working of gelatine and collodion emulsion processes
A photography manual by William de Wiveleslie Abney, published in New York in 1882 by the Scovill Manufacturing Company, addressed to practitioners of gelatine and collodion emulsion processes. The pictures are plain line engravings of laboratory apparatus: a heated drying box with a suspended weight, a bottle set inside a cylinder with a tube, a two-chamber siphon-like vessel, and a glass test tube with side arms. A designer could take their clean, schematic diagram style, with lettered reference points and simple labelled hardware, as a model for technical instructional drawings.
