1912. Second Edition. 125 pages. No dust jacket. This is an ex-Library book. Green cloth with black lettering. Contains black and white diagrams throughout. Expected library inserts, stamps and inscriptions. Pages are mildly tanned and foxed, but text remains clear. Binding is firm. Boards have light shelf-wear, with noticeable corner bumping. Spine is slightly tanned, with mild crushing to ends. Faint black marks overall.