1938. Third Edition. 144 pages. Illustrated dust jacket over blue cloth boards. Contains black and white illustrations. Contains folded drawings about signals. Slight crinkling to paper at gutter. Clean pages and illustrations with light tanning and foxing to text block edges. Binding is firm throughout with minor thumb-marking. Heavier tanning to free endpapers. Boards have mild edge-wear with slight rubbing to surfaces and bumping to corners. Slight crushing to spine ends. Unclipped jacket. Panels and spine have moderate edgewear with chips, tears and creases. Moderate loss to spine. Moderate tanning and pen markings to flaps, panels and spine.