Enlarged images to show illusion of tone

Detail of Letterpress from wood engraving and metal type.  J. H. Rimbault. Compound Semi-fixed Engine from the journal Engineering, December 8, 1882. 1882. 12 x 8 3/4" (30.5 x 22.2 cm).

The horizontal lines describing the roundness of the engine’s cylinder move flawlessly from thin black lines on a white ground to equally thin white lines on a black ground. The scheme in no way mirrors the actual appearance of such a cylinder; instead it is a printer’s invention, reflecting a theoretical conception of how such a form might be described. This picture comes not from an interpreted observation of the world but from the mind of its maker.

Letterpress from wood engraving and metal type.  J. H. Rimbault. Compound Semi-fixed Engine from the journal Engineering, December 8, 1882. 1882. 12 x 8 3/4" (30.5 x 22.2 cm).