1930. First Edition. 150 pages. No dust jacket. Signed by the author. Purple cloth. Flat signed by author to front pastedown. Pull-out diagrams through book. Binding remains firm. Pages have light tanning and foxing throughout. Heavier to endpapers and pastedowns. Markings to some pages. Previous owner's inscriptions to front free endpaper. Pull-out diagrams have small tears to edges. Boards have light shelf-wear with corner bumping. Moderate sunning to spine and edges with crushing to spine ends. Slight staining to front board.