A text-book on roofs and bridges
A civil engineering textbook by Mansfield Merriman and Henry S. Jacoby, published by Wiley in New York in 1903 for students and practising bridge and roof designers. The plates are fine line diagrams: arched and braced trusses drawn in outline beside force polygons and reaction diagrams, with dashed construction lines, arrows and italic letter labels that a designer can lift as technical linework or abstract linear pattern.
