The elements of railroad engineering
A technical instruction manual on railroad engineering issued by the International Correspondence Schools in Scranton, Pennsylvania, in 1897 for correspondence students training as surveyors and railway engineers. The 91 figures are small line-engraved diagrams — U-tubes of shaded liquid, hoop sections with force arrows, hatched masonry, pulley-and-weight rigs — built from hand-ruled hatching and italic letter keys.
