Mechanical drawing: lettering, materials and methods
A 1916 instructional manual on mechanical drawing and lettering by Frank R. Kepler, issued by the Detroit Board of Education for use in public school drafting classes. The plates are spare line diagrams printed on tinted stock: set squares and T-square positions, dashed construction lines, circles divided into angles, and orthographic projections of a square above a ground line, useful as ready-made technical line motifs and drafting iconography.
