1968. Fourth Edition. 611 pages. Pictorial dust jacket over blue cloth. Contains black and white illustrations and photographs throughout. Bright and clean pages with light tanning to text block edges. Binding is firm throughout with minor thumb-marking. Faint tanning and foxing to endpapers. Mild staining to front endpaper. Boards have light edgewear with corner crushing and notable marking to boards. Mild tanning to board edges and spine, which has mild crushing to ends. Book has forward lean. Unclipped jacket has moderate edgewear with chips, tears, and creasing. Notable tape staining to edges. Notable rubbing and marking all over. Moderate tanning to spine.