Trigonometry, surveying and navigation
A 1903 mathematics textbook by George Albert Wentworth, issued by Ginn & Company of Boston for American secondary and college students studying trigonometry, surveying, and navigation. The plates are plain black line diagrams on tan paper: triangles with heavy and dashed sides, lettered circles with radii and chords, compass roses marked N-E-S-W, and zigzag survey traverses, useful as ready-made geometric marks, italic point labels, and construction-arc textures.
