1921. Fourth Edition. 319 pages. No dust jacket. Red cloth with embossed lettering. Contains black and white diagrams throughout. Pages are mildly tanned, but text remains clear. Binding is firm. Previous owner's inscriptions to endpapers. Boards have light shelf-wear, with mild corner bumping and minimal denting to edges. Spine is slightly tanned, with mild crushing to ends. Visible white marking overall.