1968. Fourth Edition. 492 pages. This is an ex-Library book. Red and white dust jacket over blue cloth with gilt lettering to spine. Black and white illustrations throughout. Expected library inserts, stamps and inscriptions. Binding remains firm. Pages and illustrations are lightly tanned throughout with light foxing to text block edges, front free endpaper and rear of book. Top edge of text block dyed blue. Boards have light shelf-wear with corner bumping. Slight crushing to spine ends. Gilt lettering is bright and clear. Unclipped jacket has heavy edgewear with small areas of loss to spine, tears, chips, and creasing. Holes to front panel edges. Water stains and moderate foxing to inside panels. Heavy wear marks overall.