Elementary mechanical drawing, for school and shop
A drawing manual by Frank Aborn, published in Cincinnati and New York by Van Antwerp, Bragg & Co. in 1886 for schoolboys and shop apprentices learning mechanical drafting. Plates show orthographic projections in fine line work: circles and cones with lettered points, dashed construction lines, radial division diagrams and helical developments, usable as diagram texture or geometric line ornament.
