1947. Third edition. 182 pages. Laminated pictorial dust jacket over cloth. Black and white diagrams throughout. Pages remain bright and clean with minimal tanning and foxing. Binding remains firm. A previous owner's name to front free endpaper. Boards assumed in good condition as covered with laminated jacket. Unclipped jacket has light edge wear with minor tears, chipping and creasing. Some tanning and foxing to all surfaces, particularly to spine.