1923. Second Edition. 295 pages. No dust jacket. Blue cloth. Contains some black and white diagrams and graphs. Pages are mildly tanned, but text remains clear. Binding is firm. Previous owner's inscription to front free endpaper. Pencil annotations throughout. Boards have light shelf-wear, with minor corner bumping and minimal scuffing to edges. Spine is slightly sunned, with mild crushing to ends. A few visible black marks overall.