1951. Ninth Edition. 321 pages. No dust jacket. Blue cloth with red lettering. Contains black and white diagrams throughout, with a few photographs also. Pages are mildly tanned and foxed, but text remains clear. Binding is firm. Ex-libris sticker to front free endpaper. Boards have light shelf-wear, with minor corner bumping and minimal scuffing to edges. Spine and edges are heavily sunned, with mild crushing to ends. Small visible marks overall.