Das Mikroskop, Theorie und Anwendung desselben
A German technical treatise on the microscope, its theory and use, written by botanists Carl Nägeli and Simon Schwendener and published by W. Engelmann in Leipzig in 1867 for students and working microscopists. The plates are fine-line wood-engraved optical diagrams: ray paths through lenses, circles filled with radiating spokes, labelled ellipses and axes, and concentric interference rings, useful as geometric schematics, lettered figure keys, and instrument cross-sections.
