Die Fabrikation der Theerfarbstoffe und ihrer Rohmaterialien
A German technical manual on making coal-tar dyes and their raw materials, written by W. Harmsen and published in Berlin by S. Fisher in 1889 for chemists and dye works. Its pictures are plain line diagrams of distillation stills, a sectioned apparatus with a cylinder and piston, a vessel with a stirrer and fittings, and a horizontal drum with a square frame, drawn in clean black outline with little shading, so a designer can borrow their precise, schematic line style for technical or industrial graphics.
