1947. First Edition. 123 pages. White jacket over blue cloth. Contains a few black and white diagrams. Pages are lightly tanned, but text remains clear. Binding is firm. Small brown mark to front pastedown. Boards have light shelf-wear, with minor corner bumping and minimal scuffing to edges. Minimal wear to spine. A few noticeable brown marks overall. Unclipped jacket. Light tanning to all surfaces. Panels have light edgewear, with small tears, chips and creases, heavier to spine ends. Visible marks to exterior.