Practical lessons on the lever escapement, its tests, errors, their detection and correction
A trade manual by watchmaker Thomas Jessop Wilkinson, published in Philadelphia in 1916, teaching bench workers to test and correct faults in the lever escapement. The 25 figures are hand-inked line diagrams — pallet stones, escape wheel teeth, circles divided by radii, letter-keyed geometry — offering rough brush-drawn strokes, hatching, and serif figure captions for technical collage.
